diff --git a/wp-admin/includes/class-wp-filesystem-ftpext.php b/wp-admin/includes/class-wp-filesystem-ftpext.php
index a2805da80d..54c35e6cbb 100644
--- a/wp-admin/includes/class-wp-filesystem-ftpext.php
+++ b/wp-admin/includes/class-wp-filesystem-ftpext.php
@@ -17,7 +17,7 @@
 class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	var $link;
 	var $timeout = 5;
-	var $errors = array();
+	var $errors = null;
 	var $options = array();
 
 	var $permission = null;
@@ -65,7 +65,7 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 	}
 
 	function connect() {
-		if ( $this->options['ssl'] && function_exists('ftp_ssl_connect') )
+		if ( isset($this->options['ssl']) && $this->options['ssl'] && function_exists('ftp_ssl_connect') )
 			$this->link = @ftp_ssl_connect($this->options['hostname'], $this->options['port'],$this->timeout);
 		else
 			$this->link = @ftp_connect($this->options['hostname'], $this->options['port'],$this->timeout);
@@ -187,30 +187,31 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		return ftp_rename($this->link, $source, $destination);
 	}
 
-	function delete($file,$recursive=false) {
+	function delete($file, $recursive = false ) {
+		if ( empty($file) )
+			return false;
 		if ( $this->is_file($file) )
 			return @ftp_delete($this->link, $file);
 		if ( !$recursive )
 			return @ftp_rmdir($this->link, $file);
-		$filelist = $this->dirlist($file);
-		foreach ((array) $filelist as $filename => $fileinfo) {
-			$this->delete($file . '/' . $filename, $recursive);
-		}
+
+		$filelist = $this->dirlist( trailingslashit($file) );
+		if ( !empty($filelist) )
+			foreach ( $filelist as $delete_file )
+				$this->delete( trailingslashit($file) . $delete_file['name'], $recursive);
 		return @ftp_rmdir($this->link, $file);
 	}
 
 	function exists($file) {
-		$list = ftp_rawlist($this->link, $file, false);
-		if( ! $list )
-			return false;
-		return count($list) == 1 ? true : false;
+		$list = @ftp_rawlist($this->link, $file, false);
+		return !empty($list); //empty list = no file, so invert.
 	}
 	function is_file($file) {
-		return $this->is_dir($file) ? false : true;
+		return $this->exists($file) && !$this->is_dir($file);
 	}
 	function is_dir($path) {
 		$cwd = $this->cwd();
-		$result = @ftp_chdir($this->link, $path);
+		$result = @ftp_chdir($this->link, trailingslashit($path) );
 		if( $result && $path == $this->cwd() || $this->cwd() != $cwd ) {
 			@ftp_chdir($this->link, $cwd);
 			return true;
@@ -218,7 +219,7 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		return false;
 	}
 	function is_readable($file) {
-		//Get dir list, Check if the file is writable by the current user??
+		//Get dir list, Check if the file is readable by the current user??
 		return true;
 	}
 	function is_writable($file) {
@@ -238,7 +239,7 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		return false;
 	}
 	function mkdir($path, $chmod = false, $chown = false, $chgrp = false) {
-		if( !@ftp_mkdir($this->link, $path) )
+		if( !ftp_mkdir($this->link, $path) )
 			return false;
 		if( $chmod )
 			$this->chmod($path, $chmod);
@@ -249,17 +250,14 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 		return true;
 	}
 	function rmdir($path, $recursive = false) {
-		if( ! $recursive )
-			return @ftp_rmdir($this->link, $path);
-
-		//TODO: Recursive Directory delete, Have to delete files from the folder first.
-		//$dir = $this->dirlist($path);
-		//foreach($dir as $file)
-
+		return $this->delete($path, $recursive);
 	}
 
 	function parselisting($line) {
-		$is_windows = ($this->OS_remote == FTP_OS_Windows);
+		static $is_windows;
+		if ( is_null($is_windows) )
+			$is_windows = strpos( strtolower(ftp_systype($this->link)), 'win') !== false;
+
 		if ($is_windows && preg_match("/([0-9]{2})-([0-9]{2})-([0-9]{2}) +([0-9]{2}):([0-9]{2})(AM|PM) +([0-9]+|<DIR>) +(.+)/", $line, $lucifer)) {
 			$b = array();
 			if ($lucifer[3]<70) { $lucifer[3] +=2000; } else { $lucifer[3]+=1900; } // 4digit year fix
diff --git a/wp-admin/includes/class-wp-filesystem-ftpsockets.php b/wp-admin/includes/class-wp-filesystem-ftpsockets.php
index d5ee3f97b4..759eaa821c 100644
--- a/wp-admin/includes/class-wp-filesystem-ftpsockets.php
+++ b/wp-admin/includes/class-wp-filesystem-ftpsockets.php
@@ -17,7 +17,7 @@
 class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	var $ftp = false;
 	var $timeout = 5;
-	var $errors;
+	var $errors = null;
 	var $options = array();
 
 	var $permission = null;
@@ -210,6 +210,8 @@ class WP_Filesystem_ftpsockets extends WP_Filesystem_Base {
 	}
 
 	function delete($file, $recursive = false ) {
+		if ( empty($file) )
+			return false;
 		if ( $this->is_file($file) )
 			return $this->ftp->delete($file);
 		if ( !$recursive )
diff --git a/wp-admin/includes/class-wp-upgrader.php b/wp-admin/includes/class-wp-upgrader.php
new file mode 100644
index 0000000000..b240ee26f3
--- /dev/null
+++ b/wp-admin/includes/class-wp-upgrader.php
@@ -0,0 +1,966 @@
+<?php
+/**
+ * This file is an attempt at an abstracted version of the plugin/theme/core installer/upgrader which can be used interchangably for all uses needed within WordPress.
+ * It is designed to be as flexible as possible, but some logic may seem rather, crazy to say the least.
+ * Yes, this header is designed to be replaced before commiting, Hopefully i'll get some proper documentation in here.
+ *
+ * This File obviously needs some new PHPDoc, However:
+ * Tested:
+ *   Theme/Plugin Upgrades/Installs
+ *   Core Upgrade
+ *   FTP Extension, FTP Sockets, Direct.
+ * Untested:
+ *   SSH2 Layer - Needs a good cleanup.
+ *
+ * TODO: Remove this commentblock and replace with some better docs.
+ */
+
+class WP_Upgrader {
+	var $strings = array();
+	var $skin = null;
+	var $result = array();
+	
+	function WP_Upgrader(&$skin = null) {
+		return __construct($skin);
+	}
+	function __construct(&$skin = null) {
+		if ( null == $skin )
+			$this->skin = new WP_Upgrader_Skin();
+		else
+			$this->skin = $skin;
+		$this->skin->set_upgrader($this);
+	}
+	
+	function generic_strings() {
+		$this->strings['bad_request'] = __('Invalid Data provided.');
+		$this->strings['fs_unavailable'] = __('Could not access filesystem.');
+		$this->strings['fs_error'] = __('Filesystem error');
+		$this->strings['fs_no_root_dir'] = __('Unable to locate WordPress Root directory.');
+		$this->strings['fs_no_content_dir'] = __('Unable to locate WordPress Content directory (wp-content).');
+		$this->strings['fs_no_plugins_dir'] = __('Unable to locate WordPress Plugin directory.');
+		$this->strings['fs_no_themes_dir'] = __('Unable to locate WordPress Theme directory.');
+		$this->strings['fs_no_folder'] = __('Unable to locate needed folder (%s).');
+
+		$this->strings['download_failed'] = __('Download failed.');
+		$this->strings['installing_package'] = __('Installing the latest version.');
+		$this->strings['folder_exists'] = __('Destination folder already exists.');
+		$this->strings['mkdir_failed'] = __('Could not create directory.');
+		$this->strings['bad_package'] = __('Incompatible Archive');
+		
+		$this->strings['maintenance_start'] = __('Enabling Maintenance mode.');
+		$this->strings['maintenance_end'] = __('Disabling Maintenance mode.');
+	}
+	
+	function fs_connect( $directories = array() ) {
+		global $wp_filesystem;
+	
+		if ( false === ($credentials = $this->skin->request_filesystem_credentials()) ) //request_filesystem_credentials($url)) )
+			return false;
+	
+		if ( ! WP_Filesystem($credentials) ) {
+			$error = true;
+			if ( is_object($wp_filesystem) && $wp_filesystem->errors->get_error_code() )
+				$error = $wp_filesystem->errors;
+			$this->skin->request_filesystem_credentials($error); //Failed to connect, Error and request again
+			return false;
+		}
+
+		if ( ! is_object($wp_filesystem) )
+			return new WP_Error('fs_unavailable', $this->strings['fs_unavailable'] );
+	
+		if ( is_wp_error($wp_filesystem->errors) && $wp_filesystem->errors->get_error_code() )
+			return new WP_Error('fs_error', $this->strings['fs_error'], $wp_filesystem->errors);
+
+		foreach ( (array)$directories as $dir ) {
+			if ( ABSPATH == $dir && ! $wp_filesystem->abspath() )
+				return new WP_Error('fs_no_root_dir', $this->strings['fs_no_root_dir']);
+
+			elseif ( WP_CONTENT_DIR == $dir && ! $wp_filesystem->wp_content_dir() )
+				return new WP_Error('fs_no_content_dir', $this->strings['fs_no_content_dir']);
+
+			elseif ( WP_PLUGIN_DIR == $dir && ! $wp_filesystem->wp_plugins_dir() )
+				return new WP_Error('fs_no_plugins_dir', $this->strings['fs_no_plugins_dir']);
+
+			elseif ( WP_CONTENT_DIR . '/themes' == $dir && ! $wp_filesystem->find_folder(WP_CONTENT_DIR . '/themes') )
+				return new WP_Error('fs_no_themes_dir', $this->strings['fs_no_themes_dir']);
+
+			elseif ( ! $wp_filesystem->find_folder($dir) )
+				return new WP_Error('fs_no_folder', sprintf($strings['fs_no_folder'], $dir));
+		}
+		return true;
+	} //end fs_connect();
+
+	function download_package($package) {
+
+		if ( ! preg_match('!^(http|https|ftp)://!i', $package) && file_exists($package) ) //Local file or remote?
+			return $package; //must be a local file..
+		
+		if ( empty($package) )
+			return new WP_Error('no_package', $this->strings['no_package']);
+
+		$this->skin->feedback('downloading_package', $package);
+
+		$download_file = download_url($package);
+	
+		if ( is_wp_error($download_file) )
+			return new WP_Error('download_failed', $this->strings['download_failed'], $download_file->get_error_message());
+		
+		return $download_file;
+	}
+	
+	function unpack_package($package, $delete_package = true) {
+		global $wp_filesystem;
+		
+		$this->skin->feedback('unpack_package');
+
+		$upgrade_folder = $wp_filesystem->wp_content_dir() . 'upgrade/';
+
+		//Clean up contents of upgrade directory beforehand.
+		$upgrade_files = $wp_filesystem->dirlist($upgrade_folder);
+		if ( !empty($upgrade_files) ) {
+			foreach ( $upgrade_files as $file )
+				$wp_filesystem->delete($upgrade_folder . $file['name'], true);
+		}
+
+		//We need a working directory
+		$working_dir = $upgrade_folder . basename($package, '.zip');
+
+		// Clean up working directory
+		if ( $wp_filesystem->is_dir($working_dir) )
+			$wp_filesystem->delete($working_dir, true);
+
+		// Unzip package to working directory
+		$result = unzip_file($package, $working_dir); //TODO optimizations, Copy when Move/Rename would suffice?
+
+		// Once extracted, delete the package if required.
+		if ( $delete_package )
+			unlink($package);
+
+		if ( is_wp_error($result) ) {
+			$wp_filesystem->delete($working_dir, true);
+			return $result;
+		}
+		
+		return $working_dir;
+	}
+	
+	function install_package($args = array()) {
+		global $wp_filesystem;
+		$defaults = array( 'source' => '', 'destination' => '', //Please always pass these
+						'clear_destination' => false, 'clear_working' => false,
+						'hook_extra' => array());
+
+		$args = wp_parse_args($args, $defaults);
+		extract($args);
+
+		@set_time_limit( 300 );
+
+		if ( empty($source) || empty($destination) )
+			return new WP_Error('bad_request', $this->strings['bad_request']);
+		
+		$this->skin->feedback('installing_package');
+
+		$res = apply_filters('upgrader_pre_install', true, $hook_extra);
+		if ( is_wp_error($res) )
+			return $res;
+
+		//Retain the Original source and destinations
+		$remote_source = $source;
+		$local_destination = $destination;
+		
+		$source_files = array_keys( $wp_filesystem->dirlist($remote_source) );
+		$remote_destination = $wp_filesystem->find_folder($local_destination);
+
+		//Locate which directory to copy to the new folder, This is based on the actual folder holding the files.
+		if ( 1 == count($source_files) && $wp_filesystem->is_dir( trailingslashit($source) . $source_files[0] . '/') ) //Only one folder? Then we want its contents.
+			$source = trailingslashit($source) . trailingslashit($source_files[0]);
+		elseif ( count($source_files) == 0 )
+			return new WP_Error('bad_package', $this->strings['bad_package']); //There are no files?
+		//else //Its only a single file, The upgrader will use the foldername of this file as the destination folder. foldername is based on zip filename.
+				  
+		//Hook ability to change the source file location..
+		$source = apply_filters('upgrader_source_selection', $source, $remote_source, $this);
+		if ( is_wp_error($source) )
+			return $source;
+		
+		//Has the source location changed? If so, we need a new source_files list.
+		if ( $source !== $remote_source )
+			$source_files = array_keys( $wp_filesystem->dirlist($source) );
+		
+		//Protection against deleting files in any important base directories.
+		if ( in_array( $destination, array(ABSPATH, WP_CONTENT_DIR, WP_PLUGIN_DIR, WP_CONTENT_DIR . '/themes') ) ) {
+			$remote_destination = trailingslashit($remote_destination) . trailingslashit(basename($source));
+			$destination = trailingslashit($destination) . trailingslashit(basename($source));
+		}
+
+		//If we're not clearing the destination folder, and something exists there allready, Bail.
+		if ( ! $clear_destination && $wp_filesystem->exists($remote_destination) ) {
+			$wp_filesystem->delete($remote_source, true); //Clear out the source files.
+			return new WP_Error('folder_exists', $this->strings['folder_exists'], $remote_destination );
+		} else if ( $clear_destination ) {
+			//We're going to clear the destination if theres something there
+			$this->skin->feedback('remove_old');
+
+			$removed = true;
+			if ( $wp_filesystem->exists($remote_destination) )
+				$removed = $wp_filesystem->delete($remote_destination, true);
+
+			$removed = apply_filters('upgrader_clear_destination', $removed, $local_destination, $remote_destination, $hook_extra);
+
+			if ( is_wp_error($removed) )
+				return $removed;
+			else if ( ! $removed )
+				return new WP_Error('remove_old_failed', $this->strings['remove_old_failed']);
+		}
+		
+		//Create destination if needed
+		if ( !$wp_filesystem->exists($remote_destination) )
+			if ( !$wp_filesystem->mkdir($remote_destination, FS_CHMOD_DIR) )
+				return new WP_Error('mkdir_failed', $this->strings['mkdir_failed'], $remote_destination);
+		
+		// Copy new version of item into place.
+		$result = copy_dir($source, $remote_destination);
+		if ( is_wp_error($result) ) {
+			if ( $clear_working )
+				$wp_filesystem->delete($remote_source, true);
+			return $result;
+		}
+		
+		//Clear the Working folder? 
+		if ( $clear_working )
+			$wp_filesystem->delete($remote_source, true);
+		
+		$destination_name = basename( str_replace($local_destination, '', $destination) );
+		if ( '.' == $destination_name )
+			$destination_name = '';
+
+		$this->result = compact('local_source', 'source', 'source_name', 'source_files', 'destination', 'destination_name', 'local_destination', 'remote_destination', 'clear_destination', 'delete_source_dir');
+
+		$res = apply_filters('upgrader_post_install', true, $hook_extra, $this->result);
+		if ( is_wp_error($res) ) {
+			$this->result = $res;
+			return $res;
+		}
+
+		//Bombard the calling function will all the info which we've just used.
+		return $this->result;
+	}
+	
+	function run($options) {
+
+		$defaults = array( 	'package' => '', //Please always pass this.
+							'destination' => '', //And this
+							'clear_destination' => false,
+							'clear_working' => true,
+							'hook_extra' => array() //Pass any extra $hook_extra args here, this will be passed to any hooked filters.
+						);
+
+		$options = wp_parse_args($options, $defaults);
+		extract($options);
+
+		$this->skin->header();
+		$this->skin->before();
+		
+		//Connect to the Filesystem first.
+		$res = $this->fs_connect( array(WP_CONTENT_DIR, $destination) );
+		if ( ! $res ) //Mainly for non-connected filesystem.
+			return false;
+
+		if ( is_wp_error($res) ) {
+			$this->skin->error($res);
+			return $res;
+		}
+		
+		//Download the package (Note, This just returns the filename of the file if the package is a local file)
+		$download = $this->download_package( $package );
+		if ( is_wp_error($download) ) {
+			$this->skin->error($download);
+			return $download;
+		}
+		
+		//Unzip's the file into a temporary directory
+		$working_dir = $this->unpack_package( $download );
+		if ( is_wp_error($working_dir) ) {
+			$this->skin->error($working_dir);
+			return $working_dir;
+		}
+
+		//With the given options, this installs it to the destination directory.
+		$result = $this->install_package( array( 
+											'source' => $working_dir,
+											'destination' => $destination,
+											'clear_destination' => $clear_destination,
+											'clear_working' => $clear_working,
+											'hook_extra' => $hook_extra
+										) );
+		$this->skin->set_result($result);
+		if ( is_wp_error($result) ) {
+			$this->skin->error($result);
+			$this->skin->feedback('process_failed');
+		} else {
+			//Install Suceeded
+			$this->skin->feedback('process_success');
+		}
+		$this->skin->after();
+		$this->skin->footer();
+		return $result;
+	}
+	
+	function maintenance_mode($enable = false) {
+		global $wp_filesystem;
+		$file = $wp_filesystem->abspath() . '.maintenance';
+		if ( $enable ) {
+			$this->skin->feedback('maintenance_start');
+			// Create maintenance file to signal that we are upgrading
+			$maintenance_string = '<?php $upgrading = ' . time() . '; ?>';
+			$wp_filesystem->delete($file);
+			$wp_filesystem->put_contents($file, $maintenance_string, FS_CHMOD_FILE);
+		} else if ( !$enable && $wp_filesystem->exists($file) ) {
+			$this->skin->feedback('maintenance_end');
+			$wp_filesystem->delete($file);
+		}
+	}
+	
+}
+
+class Plugin_Upgrader extends WP_Upgrader {
+
+	var $result;
+	
+	function upgrade_strings() {
+		$this->generic_strings();
+		$this->strings['up_to_date'] = __('The plugin is at the latest version.');
+		$this->strings['no_package'] = __('Upgrade package not available.');
+		$this->strings['downloading_package'] = __('Downloading update from %s.');
+		$this->strings['unpack_package'] = __('Unpacking the update.');
+		$this->strings['deactivate_plugin'] = __('Deactivating the plugin.');
+		$this->strings['remove_old'] = __('Removing the old version of the plugin.');
+		$this->strings['remove_old_failed'] = __('Could not remove the old plugin.');
+		$this->strings['process_failed'] = __('Plugin upgrade Failed.');
+		$this->strings['process_success'] = __('Plugin upgraded successfully.');
+	}
+
+	function install_strings() {
+		$this->generic_strings();
+		$this->strings['no_package'] = __('Install package not available.');
+		$this->strings['downloading_package'] = __('Downloading install package from %s.');
+		$this->strings['unpack_package'] = __('Unpacking the package.');
+		$this->strings['installing_package'] = __('Installing the plugin.');
+		$this->strings['process_failed'] = __('Plugin Install Failed.');
+		$this->strings['process_success'] = __('Plugin Installed successfully.');
+	}
+
+	function install($package) {
+		
+		$this->install_strings();
+
+		$this->run(array(
+					'package' => $package,
+					'destination' => WP_PLUGIN_DIR,
+					'clear_destination' => false, //Do not overwrite files.
+					'clear_working' => true,
+					'hook_extra' => array()
+					));
+	
+		// Force refresh of plugin update information
+		delete_transient('update_plugins');
+
+	}
+
+	function upgrade($plugin) {
+		
+		$this->upgrade_strings();
+		
+		$current = get_transient( 'update_plugins' );
+		if ( !isset( $current->response[ $plugin ] ) ) {
+			$this->skin->error('up_to_date');
+			return false;
+			//return new WP_Error('up_to_date', $this->strings['up_to_date']);
+		}
+
+		// Get the URL to the zip file
+		$r = $current->response[ $plugin ];
+		
+		add_filter('upgrader_pre_install', array(&$this, 'deactivate_plugin_before_upgrade'), 10, 2);
+		add_filter('upgrader_clear_destination', array(&$this, 'delete_old_plugin'), 10, 4);
+		//'source_selection' => array(&$this, 'source_selection'), //theres a track ticket to move up the directory for zip's which are made a bit differently, useful for non-.org plugins.
+
+		$this->run(array(
+					'package' => $r->package,
+					'destination' => WP_PLUGIN_DIR,
+					'clear_destination' => true,
+					'clear_working' => true,
+					'hook_extra' => array(
+								'plugin' => $plugin
+					)
+				));
+
+		//Cleanup our hooks, incase something else does a upgrade on this connection.
+		remove_filter('upgrader_pre_install', array(&$this, 'deactivate_plugin_before_upgrade'));
+		remove_filter('upgrader_clear_destination', array(&$this, 'delete_old_plugin'));
+
+		if ( ! $this->result || is_wp_error($this->result) )
+			return $this->result;
+
+		// Force refresh of plugin update information
+		delete_transient('update_plugins');
+	}
+	
+	//return plugin info.
+	function plugin_info() {
+		if ( ! is_array($this->result) )
+			return false;
+		if ( empty($this->result['destination_name']) )
+			return false; 
+
+		$plugin = get_plugins('/' . $this->result['destination_name']); //Ensure to pass with leading slash
+		if ( empty($plugin) )
+			return false;
+
+		$pluginfiles = array_keys($plugin); //Assume the requested plugin is the first in the list
+
+		return $this->result['destination_name'] . '/' . $pluginfiles[0];	
+	}
+
+	//Hooked to pre_install
+	function deactivate_plugin_before_upgrade($return, $plugin) {
+
+		if ( is_wp_error($return) ) //Bypass.
+			return $return;
+
+		$plugin = isset($plugin['plugin']) ? $plugin['plugin'] : '';
+		if ( empty($plugin) )
+			return new WP_Error('bad_request', $this->strings['bad_request']);
+
+		if ( is_plugin_active($plugin) ) {
+			$this->skin->feedback('deactivate_plugin');
+			//Deactivate the plugin silently, Prevent deactivation hooks from running.
+			deactivate_plugins($plugin, true);
+		}	
+	}
+
+	//Hooked to upgrade_clear_destination
+	function delete_old_plugin($removed, $local_destination, $remote_destination, $plugin) {
+		global $wp_filesystem;
+	
+		if ( is_wp_error($removed) )
+			return $removed; //Pass errors through.
+	
+		$plugin = isset($plugin['plugin']) ? $plugin['plugin'] : '';
+		if ( empty($plugin) )
+			return new WP_Error('bad_request', $this->strings['bad_request']);
+
+		$plugins_dir = $wp_filesystem->wp_plugins_dir();
+		$this_plugin_dir = trailingslashit( dirname($plugins_dir . $plugin) );
+		
+		if ( ! $wp_filesystem->exists($this_plugin_dir) ) //If its already vanished.
+			return $removed;
+	
+		// If plugin is in its own directory, recursively delete the directory.
+		if ( strpos($plugin, '/') && $this_plugin_dir != $plugins_dir ) //base check on if plugin includes directory seperator AND that its not the root plugin folder
+			$deleted = $wp_filesystem->delete($this_plugin_dir, true);
+		else
+			$deleted = $wp_filesystem->delete($plugins_dir . $plugin);
+
+		if ( ! $deleted )
+			return new WP_Error('remove_old_failed', $this->strings['remove_old_failed']);
+		
+		return $removed;
+	}
+}
+
+
+class Theme_Upgrader extends WP_Upgrader {
+
+	var $result;
+
+	function upgrade_strings() {
+		$this->generic_strings();
+		$this->strings['up_to_date'] = __('The theme is at the latest version.');
+		$this->strings['no_package'] = __('Upgrade package not available.');
+		$this->strings['downloading_package'] = __('Downloading update from %s.');
+		$this->strings['unpack_package'] = __('Unpacking the update.');
+		$this->strings['remove_old'] = __('Removing the old version of the theme.');
+		$this->strings['remove_old_failed'] = __('Could not remove the old theme.');
+		$this->strings['process_failed'] = __('Theme upgrade Failed.');
+		$this->strings['process_success'] = __('Theme upgraded successfully.');
+	}
+
+	function install_strings() {
+		$this->generic_strings();
+		$this->strings['no_package'] = __('Install package not available.');
+		$this->strings['downloading_package'] = __('Downloading install package from %s.');
+		$this->strings['unpack_package'] = __('Unpacking the package.');
+		$this->strings['installing_package'] = __('Installing the theme.');
+		$this->strings['process_failed'] = __('Theme Install Failed.');
+		$this->strings['process_success'] = __('Theme Installed successfully.');
+	}
+
+	function install($package) {
+		
+		$this->install_strings();
+
+		$options = array(
+						'package' => $package,
+						'destination' => WP_CONTENT_DIR . '/themes',
+						'clear_destination' => false, //Do not overwrite files.
+						'clear_working' => true
+						);
+		
+		$this->run($options);
+	
+		if ( ! $this->result || is_wp_error($this->result) )
+			return $this->result;
+	
+		// Force refresh of theme update information
+		delete_transient('update_themes');
+	
+		if ( empty($result['destination_name']) )
+			return false; 
+		else
+			return $result['destination_name'];
+	}
+
+	function upgrade($theme) {
+		
+		$this->upgrade_strings();
+		
+		// Is an update available?
+		$current = get_transient( 'update_themes' );
+		if ( !isset( $current->response[ $theme ] ) )
+			return new WP_Error('up_to_date', $this->strings['up_to_date']);
+		
+		$r = $current->response[ $theme ];
+
+		add_filter('upgrader_pre_install', array(&$this, 'current_before'), 10, 2);
+		add_filter('upgrader_post_install', array(&$this, 'current_after'), 10, 2);
+		add_filter('upgrader_clear_destination', array(&$this, 'delete_old_theme'), 10, 4);
+
+		$options = array(
+						'package' => $r['package'],
+						'destination' => WP_CONTENT_DIR . '/themes',
+						'clear_destination' => true,
+						'clear_working' => true,
+						'hook_extra' => array(
+											'theme' => $theme
+											)
+						);
+		
+		$this->run($options);
+
+		if ( ! $this->result || is_wp_error($this->result) )
+			return $this->result;
+
+		// Force refresh of theme update information
+		delete_transient('update_themes');
+
+		return true;
+	}
+	
+	function current_before($return, $theme) {
+		
+		if ( is_wp_error($return) )
+			return $return;
+
+		$theme = isset($theme['theme']) ? $theme['theme'] : '';
+
+		if ( $theme != get_stylesheet() ) //If not current
+			return $return;
+		//Change to maintainence mode now.
+		$this->maintenance_mode(true);
+
+		return $return;
+	}
+	function current_after($return, $theme) {
+		if ( is_wp_error($return) )
+			return $return;
+
+		$theme = isset($theme['theme']) ? $theme['theme'] : '';
+
+		if ( $theme != get_stylesheet() ) //If not current
+			return $return;
+
+		//Ensure stylesheet name hasnt changed after the upgrade:
+		if ( $theme == get_stylesheet() && $theme != $this->result['destination_name'] ) {
+			$theme_info = $this->theme_info();
+			$stylesheet = $this->result['destination_name'];
+			$template = !empty($theme_info['Template']) ? $theme_info['Template'] : $stylesheet;
+			switch_theme($template, $stylesheet, true);
+		}
+
+		//Time to remove maintainence mode
+		$this->maintenance_mode(false);
+		return $return;
+	}
+	
+	function delete_old_theme($removed, $local_destination, $remote_destination, $theme) {
+		global $wp_filesystem;
+	
+		$theme = isset($theme['theme']) ? $theme['theme'] : '';
+	
+		if ( is_wp_error($removed) || empty($theme) )
+			return $removed; //Pass errors through.
+		
+		$themes_dir = $wp_filesystem->wp_themes_dir();
+		if ( $wp_filesystem->exists( trailingslashit($themes_dir) . $theme ) )
+			if ( ! $wp_filesystem->delete( trailingslashit($themes_dir) . $theme, true ) )
+				return false;
+		return true;
+	}
+	
+	function theme_info() {
+		if ( empty($this->result['destination_name']) )
+			return false;
+		return get_theme_data(WP_CONTENT_DIR . '/themes/' . $this->result['destination_name'] . '/style.css');
+	}
+
+}
+
+//Untested.
+class Core_Upgrader extends WP_Upgrader {
+
+	function upgrade_strings() {
+		$this->generic_strings();
+		$this->strings['up_to_date'] = __('WordPress is at the latest version.');
+		$this->strings['no_package'] = __('Upgrade package not available.');
+		$this->strings['downloading_package'] = __('Downloading update from %s.');
+		$this->strings['unpack_package'] = __('Unpacking the update.');
+		$this->strings['copy_failed'] = __('Could not copy files.');
+	}
+
+	function upgrade($current) {
+		global $wp_filesystem;
+		$this->upgrade_strings();
+		
+	
+		if ( !empty($feedback) )
+			add_filter('update_feedback', $feedback);
+	
+		// Is an update available?
+		if ( !isset( $current->response ) || $current->response == 'latest' )
+			return new WP_Error('up_to_date', $this->strings['up_to_date']);
+
+		$res = $this->fs_connect( array(ABSPATH, WP_CONTENT_DIR) );
+		if ( is_wp_error($res) )
+			return $res;
+		
+		$wp_dir = trailingslashit($wp_filesystem->abspath());
+		
+		$download = $this->download_package( $current->package );
+		if ( is_wp_error($download) )
+			return $download;
+		
+		$working_dir = $this->unpack_package( $download );
+		if ( is_wp_error($working_dir) )
+			return $working_dir;
+
+		// Copy update-core.php from the new version into place.
+		if ( !$wp_filesystem->copy($working_dir . '/wordpress/wp-admin/includes/update-core.php', $wp_dir . 'wp-admin/includes/update-core.php', true) ) {
+			$wp_filesystem->delete($working_dir, true);
+			return new WP_Error('copy_failed', $this->strings['copy_failed']);
+		}
+		$wp_filesystem->chmod($wp_dir . 'wp-admin/includes/update-core.php', FS_CHMOD_FILE);
+	
+		require(ABSPATH . 'wp-admin/includes/update-core.php');
+	
+		return update_core($working_dir, $wp_dir);
+	}
+
+}
+
+
+/**
+ * Skin stuff here.
+ * ============================================
+ * ============================================
+ * ============================================
+ */
+
+class WP_Upgrader_Skin {
+	
+	var $upgrader;
+	var $done_header = false;
+	
+	function WP_Upgrader_Skin($args = array()) {
+		return __construct($args);
+	}
+	function __construct($args = array()) {
+		$defaults = array( 'url' => '', 'nonce' => '', 'title' => '' );
+		$this->options = wp_parse_args($args, $defaults);
+	}
+	
+	function set_upgrader(&$upgrader) {
+		if ( is_object($upgrader) )
+			$this->upgrader =& $upgrader;
+	}
+	function set_result($result) {
+		$this->result = $result;
+	}
+	
+	function request_filesystem_credentials($error = false) {
+		$url = $this->options['url'];
+		if ( !empty($this->options['nonce']) )
+			$url = wp_nonce_url($url, $this->options['nonce']);
+		return request_filesystem_credentials($url, '', $error); //Possible to bring inline, Leaving as0is for now.
+	}
+	
+	function header() {
+		if ( $this->done_header )
+			return;
+		$this->done_header = true;
+		echo '<div class="wrap">';
+		echo screen_icon();
+		echo '<h2>' . $this->options['title'] . '</h2>';	
+	}
+	function footer() {
+		echo '</div>';
+	}
+	
+	function error($errors) {
+		if ( ! $this->done_header )
+			$this->header();
+		if ( is_string($errors) ) {
+			$this->feedback($errors);
+		} elseif ( is_wp_error($errors) && $errors->get_error_code() ) {
+			foreach ( $errors->get_error_messages() as $message )
+				$this->feedback($message);
+		}
+	}
+
+	function feedback($string) {
+		if ( isset( $this->upgrader->strings[$string]) )
+			$string = $this->upgrader->strings[$string];
+
+		$args = func_get_args();
+		$args = array_splice($args, 1);
+		if ( !empty($args) )
+			$string = vsprintf($string, $args);
+		if ( empty($string) )
+			return;
+		show_message($string);
+	}	
+	function before() {}
+	function after() {}
+	
+}
+
+class Plugin_Upgrader_Skin extends WP_Upgrader_Skin {
+	var $plugin = '';
+	var $plugin_active = false;
+
+	function Plugin_Upgrader_Skin($args = array()) {
+		return __construct($args);
+	}
+
+	function __construct($args = array()) {
+		$defaults = array( 'url' => '', 'plugin' => '', 'nonce' => '', 'title' => __('Upgrade Plugin') );
+		$args = wp_parse_args($args, $defaults);
+
+		$this->plugin = $args['plugin'];
+
+		$this->plugin_active = is_plugin_active($this->plugin);
+		
+		parent::__construct($args);
+	}
+	
+	function after() {
+		$this->plugin = $this->upgrader->plugin_info();
+		if( !empty($this->plugin) && !is_wp_error($this->result) && $this->plugin_active ){
+			show_message(__('Attempting reactivation of the plugin'));
+			echo '<iframe style="border:0;overflow:hidden" width="100%" height="170px" src="' . wp_nonce_url('update.php?action=activate-plugin&plugin=' . $this->plugin, 'activate-plugin_' . $this->plugin) .'"></iframe>';
+		}
+		$update_actions =  array(
+			'activate_plugin' => '<a href="' . wp_nonce_url('plugins.php?action=activate&amp;plugin=' . $this->plugin, 'activate-plugin_' . $this->plugin) . '" title="' . attribute_escape(__('Activate this plugin')) . '" target="_parent">' . __('Activate Plugin') . '</a>',
+			'plugins_page' => '<a href="' . admin_url('plugins.php') . '" title="' . attribute_escape(__('Goto plugins page')) . '" target="_parent">' . __('Return to Plugins page') . '</a>'
+		);
+		if ( $this->plugin_active )
+			unset( $update_actions['activate_plugin'] );
+		if ( ! $this->result || is_wp_error($this->result) )
+			unset( $update_actions['activate_plugin'] );
+
+		$update_actions = apply_filters('update_plugin_complete_actions', $update_actions, $this->plugin);
+		if ( ! empty($update_actions) )
+			$this->feedback('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$update_actions));
+	}
+}
+
+
+class Plugin_Installer_Skin extends WP_Upgrader_Skin {
+	var $api;
+	var $type;
+
+	function Plugin_Installer_Skin($args = array()) {
+		return __construct($args);
+	}
+
+	function __construct($args = array()) {
+		$defaults = array( 'type' => 'web', 'url' => '', 'plugin' => '', 'nonce' => '', 'title' => '' );
+		$args = wp_parse_args($args, $defaults);
+		
+		$this->type = $args['type'];
+		$this->api = isset($args['api']) ? $args['api'] : array();
+		
+		parent::__construct($args);
+	}
+
+	function before() {
+		if ( !empty($this->api) )
+			$this->upgrader->strings['process_success'] = sprintf( __('Successfully installed the plugin <strong>%s %s</strong>.'), $this->api->name, $this->api->version);
+	}
+	
+	function after() {
+
+		$plugin_file = $this->upgrader->plugin_info();
+
+		$install_actions = array(
+			'activate_plugin' => '<a href="' . wp_nonce_url('plugins.php?action=activate&amp;plugin=' . $plugin_file, 'activate-plugin_' . $plugin_file) . '" title="' . attribute_escape(__('Activate this plugin')) . '" target="_parent">' . __('Activate Plugin') . '</a>',
+							);
+
+		if ( $this->type == 'web' )
+			$install_actions['plugins_page'] = '<a href="' . admin_url('plugin-install.php') . '" title="' . attribute_escape(__('Return to Plugin Installer')) . '" target="_parent">' . __('Return to Plugin Installer') . '</a>';
+		else
+			$install_actions['plugins_page'] = '<a href="' . admin_url('plugins.php') . '" title="' . attribute_escape(__('Return to Plugins page')) . '" target="_parent">' . __('Return to Plugins page') . '</a>';
+
+
+		if ( ! $this->result || is_wp_error($this->result) )
+			unset( $update_actions['activate_plugin'] );
+
+		$install_actions = apply_filters('install_plugin_complete_actions', $install_actions, $this->api, $plugin_file);
+		if ( ! empty($install_actions) )
+			$this->feedback('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
+	}
+}
+
+class Theme_Installer_Skin extends WP_Upgrader_Skin {
+	var $api;
+	var $type;
+
+	function Theme_Installer_Skin($args = array()) {
+		return __construct($args);
+	}
+
+	function __construct($args = array()) {
+		$defaults = array( 'type' => 'web', 'url' => '', 'theme' => '', 'nonce' => '', 'title' => '' );
+		$args = wp_parse_args($args, $defaults);
+		
+		$this->type = $args['type'];
+		$this->api = isset($args['api']) ? $args['api'] : array();
+		
+		parent::__construct($args);
+	}
+
+	function before() {
+		if ( !empty($this->api) )
+			$this->upgrader->strings['process_success'] = sprintf( __('Successfully installed the theme <strong>%s %s</strong>.'), $this->api->name, $this->api->version);
+	}
+	
+	function after() {
+		if ( empty($this->upgrader->result['destination_name']) )
+			return;
+
+		$theme_info = $this->upgrader->theme_info();
+		if ( empty($theme_info) )
+			return;
+		$name = $theme_info['Name'];
+		$stylesheet = $this->upgrader->result['destination_name'];
+		$template = !empty($theme_info['Template']) ? $theme_info['Template'] : $stylesheet;
+		
+		$preview_link = htmlspecialchars( add_query_arg( array('preview' => 1, 'template' => $template, 'stylesheet' => $stylesheet, 'TB_iframe' => 'true' ), trailingslashit(clean_url(get_option('home'))) ) );
+		$activate_link = wp_nonce_url("themes.php?action=activate&amp;template=" . urlencode($template) . "&amp;stylesheet=" . urlencode($stylesheet), 'switch-theme_' . $template);
+		
+		$install_actions = array(
+			'preview' => '<a href="' . $preview_link . '" class="thickbox thickbox-preview" title="' . attribute_escape(sprintf(__('Preview "%s"'), $name)) . '">' . __('Preview') . '</a>',
+			'activate' => '<a href="' . $activate_link .  '" class="activatelink" title="' . attribute_escape( sprintf( __('Activate "%s"'), $name ) ) . '">' . __('Activate') . '</a>'
+							);
+
+		if ( $this->type == 'web' )
+			$install_actions['themes_page'] = '<a href="' . admin_url('theme-install.php') . '" title="' . attribute_escape(__('Back to Theme Installer')) . '" target="_parent">' . __('Return to Theme Installer.') . '</a>';
+		else
+			$install_actions['themes_page'] = '<a href="' . admin_url('themes.php') . '" title="' . attribute_escape(__('Themes page')) . '" target="_parent">' . __('Return to Themes page') . '</a>';
+
+		if ( ! $this->result || is_wp_error($this->result) )
+			unset( $update_actions['activate'], $update_actions['preview'] );
+
+		$install_actions = apply_filters('install_theme_complete_actions', $install_actions, $this->api, $stylesheet, $theme_info);
+		if ( ! empty($install_actions) )
+			$this->feedback('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
+	}
+}
+
+class Theme_Upgrader_Skin extends WP_Upgrader_Skin {
+	var $theme = '';
+
+	function Theme_Upgrader_Skin($args = array()) {
+		return __construct($args);
+	}
+
+	function __construct($args = array()) {
+		$defaults = array( 'url' => '', 'theme' => '', 'nonce' => '', 'title' => __('Upgrade Theme') );
+		$args = wp_parse_args($args, $defaults);
+
+		$this->theme = $args['theme'];
+		
+		parent::__construct($args);
+	}
+	
+	function after() {
+
+		if ( empty($this->upgrader->result['destination_name']) )
+			return;
+
+		$theme_info = $this->upgrader->theme_info();
+		if ( empty($theme_info) )
+			return;
+		$name = $theme_info['Name'];
+		$stylesheet = $this->upgrader->result['destination_name'];
+		$template = !empty($theme_info['Template']) ? $theme_info['Template'] : $stylesheet;
+		
+		$preview_link = htmlspecialchars( add_query_arg( array('preview' => 1, 'template' => $template, 'stylesheet' => $stylesheet, 'TB_iframe' => 'true' ), trailingslashit(clean_url(get_option('home'))) ) );
+		$activate_link = wp_nonce_url("themes.php?action=activate&amp;template=" . urlencode($template) . "&amp;stylesheet=" . urlencode($stylesheet), 'switch-theme_' . $template);
+
+		$update_actions =  array(
+			'preview' => '<a href="' . $preview_link . '" class="thickbox thickbox-preview" title="' . attribute_escape(sprintf(__('Preview "%s"'), $name)) . '">' . __('Preview') . '</a>',
+			'activate' => '<a href="' . $activate_link .  '" class="activatelink" title="' . attribute_escape( sprintf( __('Activate "%s"'), $name ) ) . '">' . __('Activate') . '</a>',
+			'themes_page' => '<a href="' . admin_url('themes.php') . '" title="' . attribute_escape(__('Return to Themes page')) . '" target="_parent">' . __('Return to Themes page') . '</a>',
+		);
+		if ( ( ! $this->result || is_wp_error($this->result) ) || $stylesheet == get_stylesheet() )
+			unset($update_actions['preview'], $update_actions['activate']);
+	
+		$update_actions = apply_filters('update_theme_complete_actions', $update_actions, $this->theme);
+		if ( ! empty($update_actions) )
+			$this->feedback('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$update_actions));
+	}
+}
+
+class File_Upload_Upgrader {
+	var $package;
+	var $filename;
+
+	function File_Upload_Upgrader($form, $urlholder) {
+		return __construct($form, $urlholder);
+	}
+	function __construct($form, $urlholder) {
+		if ( ! ( ( $uploads = wp_upload_dir() ) && false === $uploads['error'] ) )
+			wp_die($uploads['error']);
+		
+		if ( empty($_FILES[$form]['name']) && empty($_GET[$urlholder]) )
+			wp_die(__('Please select a file'));
+	
+		if ( !empty($_FILES) )
+			$this->filename = $_FILES[$form]['name'];
+		else if ( isset($_GET[$urlholder]) )
+			$this->filename = $_GET[$urlholder];
+
+		//Handle a newly uploaded file, Else assume its already been uploaded
+		if ( !empty($_FILES) ) {
+			$this->filename = wp_unique_filename( $uploads['basedir'], $this->filename );
+			$this->package = $uploads['basedir'] . '/' . $this->filename;
+	
+			// Move the file to the uploads dir
+			if ( false === @ move_uploaded_file( $_FILES[$form]['tmp_name'], $this->package) )
+				wp_die( sprintf( __('The uploaded file could not be moved to %s.' ), $uploads['path']));
+		} else {
+			$this->package = $uploads['basedir'] . '/' . $this->filename;
+		}
+	}
+}
diff --git a/wp-admin/includes/file.php b/wp-admin/includes/file.php
index 42fa0eacc7..438f053bf8 100644
--- a/wp-admin/includes/file.php
+++ b/wp-admin/includes/file.php
@@ -598,7 +598,7 @@ function WP_Filesystem( $args = false ) {
 
 	$wp_filesystem = new $method($args);
 
-	if ( $wp_filesystem->errors->get_error_code() )
+	if ( is_wp_error($wp_filesystem->errors) && $wp_filesystem->errors->get_error_code() )
 		return false;
 
 	if ( !$wp_filesystem->connect() )
diff --git a/wp-admin/includes/plugin-install.php b/wp-admin/includes/plugin-install.php
index 9cba30787f..86f85ab152 100644
--- a/wp-admin/includes/plugin-install.php
+++ b/wp-admin/includes/plugin-install.php
@@ -208,7 +208,7 @@ function install_plugins_upload( $page = 1 ) {
 ?>
 	<h4><?php _e('Install a plugin in .zip format') ?></h4>
 	<p class="install-help"><?php _e('If you have a plugin in a .zip format, You may install it by uploading it here.') ?></p>
-	<form method="post" enctype="multipart/form-data" action="<?php echo admin_url('plugin-install.php?tab=do_upload') ?>">
+	<form method="post" enctype="multipart/form-data" action="<?php echo admin_url('update.php?action=upload-plugin') ?>">
 		<?php wp_nonce_field( 'plugin-upload') ?>
 		<input type="file" name="pluginzip" />
 		<input type="submit" class="button" value="<?php _e('Install Now') ?>" />
@@ -461,7 +461,7 @@ function install_plugin_information() {
 				default:
 				case 'install':
 					if ( current_user_can('install_plugins') ) :
-				?><a href="<?php echo wp_nonce_url(admin_url('plugin-install.php?tab=install&plugin=' . $api->slug), 'install-plugin_' . $api->slug) ?>" target="_parent"><?php _e('Install Now') ?></a><?php
+				?><a href="<?php echo wp_nonce_url(admin_url('update.php?action=install-plugin&plugin=' . $api->slug), 'install-plugin_' . $api->slug) ?>" target="_parent"><?php _e('Install Now') ?></a><?php
 					endif;
 				break;
 				case 'update_available':
@@ -544,364 +544,3 @@ function install_plugin_information() {
 	iframe_footer();
 	exit;
 }
-
-
-add_action('install_plugins_do_upload', 'upload_plugin');
-function upload_plugin() {
-
-	if ( ! ( ( $uploads = wp_upload_dir() ) && false === $uploads['error'] ) )
-		wp_die($uploads['error']);
-
-	if ( !empty($_FILES) )
-		$filename = $_FILES['pluginzip']['name'];
-	else if ( isset($_GET['package']) )
-		$filename = $_GET['package'];
-
-	check_admin_referer('plugin-upload');
-
-	echo '<div class="wrap">';
-	echo '<h2>', sprintf( __('Installing Plugin from file: %s'), basename($filename) ), '</h2>';
-
-	//Handle a newly uploaded file, Else assume it was
-	if ( !empty($_FILES) ) {
-		$filename = wp_unique_filename( $uploads['basedir'], $filename );
-		$local_file = $uploads['basedir'] . '/' . $filename;
-
-		// Move the file to the uploads dir
-		if ( false === @ move_uploaded_file( $_FILES['pluginzip']['tmp_name'], $local_file) )
-			wp_die( sprintf( __('The uploaded file could not be moved to %s.' ), $uploads['path']));
-	} else {
-		$local_file = $uploads['basedir'] . '/' . $filename;
-	}
-
-	do_plugin_install_local_package($local_file, $filename);
-	echo '</div>';
-}
-
-add_action('install_plugins_install', 'install_plugin');
-
-/**
- * Display plugin link and execute install.
- *
- * @since 2.7.0
- */
-function install_plugin() {
-
-	$plugin = isset($_REQUEST['plugin']) ? stripslashes( $_REQUEST['plugin'] ) : '';
-
-	check_admin_referer('install-plugin_' . $plugin);
-	$api = plugins_api('plugin_information', array('slug' => $plugin, 'fields' => array('sections' => false) ) ); //Save on a bit of bandwidth.
-
-	if ( is_wp_error($api) )
-		wp_die($api);
-
-	echo '<div class="wrap">';
-	echo '<h2>', sprintf( __('Installing Plugin: %s'), $api->name . ' ' . $api->version ), '</h2>';
-
-	do_plugin_install($api->download_link, $api);
-	echo '</div>';
-
-}
-
-/**
- * Retrieve plugin and install.
- *
- * @since 2.7.0
- *
- * @param string $download_url Download URL.
- * @param object $plugin_information Optional. Plugin information
- */
-function do_plugin_install($download_url, $plugin_information = null) {
-	global $wp_filesystem;
-
-	if ( empty($download_url) ) {
-		show_message( __('No plugin Specified') );
-		return;
-	}
-
-	$plugin = isset($_REQUEST['plugin']) ? stripslashes( $_REQUEST['plugin'] ) : '';
-
-	$url = 'plugin-install.php?tab=install';
-	$url = add_query_arg(array('plugin' => $plugin, 'plugin_name' => stripslashes( $_REQUEST['plugin_name'] ), 'download_url' => stripslashes( $_REQUEST['download_url'] ) ), $url);
-
-	$url = wp_nonce_url($url, 'install-plugin_' . $plugin);
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		request_filesystem_credentials($url, '', true); //Failed to connect, Error and request again
-		return;
-	}
-
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-			show_message($message);
-		return;
-	}
-
-	$result = wp_install_plugin( $download_url, 'show_message' );
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Installation Failed') );
-	} else {
-		show_message( sprintf(__('Successfully installed the plugin <strong>%s %s</strong>.'), $plugin_information->name, $plugin_information->version) );
-		$plugin_file = $result;
-
-		$install_actions = apply_filters('install_plugin_complete_actions', array(
-			'activate_plugin' => '<a href="' . wp_nonce_url('plugins.php?action=activate&amp;plugin=' . $plugin_file, 'activate-plugin_' . $plugin_file) . '" title="' . attribute_escape(__('Activate this plugin')) . '" target="_parent">' . __('Activate Plugin') . '</a>',
-			'plugins_page' => '<a href="' . admin_url('plugins.php') . '" title="' . attribute_escape(__('Goto plugins page')) . '" target="_parent">' . __('Return to Plugins page') . '</a>'
-							), $plugin_information, $plugin_file);
-		if ( ! empty($install_actions) )
-			show_message('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
-	}
-}
-
-/**
- * Install a plugin from a local file.
- *
- * @since 2.7.0
- *
- * @param string $package Local Plugin zip
- * @param string $filename Optional. Original filename
- * @param object $plugin_information Optional. Plugin information
- */
-function do_plugin_install_local_package($package, $filename = '') {
-	global $wp_filesystem;
-
-	if ( empty($package) ) {
-		show_message( __('No plugin Specified') );
-		return;
-	}
-
-	if ( empty($filename) )
-		$filename = basename($package);
-
-	$url = 'plugin-install.php?tab=upload';
-	$url = add_query_arg(array('package' => $filename), $url);
-
-	$url = wp_nonce_url($url, 'plugin-upload');
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		request_filesystem_credentials($url, '', true); //Failed to connect, Error and request again
-		return;
-	}
-
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-			show_message($message);
-		return;
-	}
-
-	$result = wp_install_plugin_local_package( $package, 'show_message' );
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Installation Failed') );
-	} else {
-		show_message( __('Successfully installed the plugin.') );
-		$plugin_file = $result;
-
-		$install_actions = apply_filters('install_plugin_complete_actions', array(
-							'activate_plugin' => '<a href="' . wp_nonce_url('plugins.php?action=activate&amp;plugin=' . $plugin_file, 'activate-plugin_' . $plugin_file) . '" title="' . __('Activate this plugin') . '" target="_parent">' . __('Activate Plugin') . '</a>',
-							'plugins_page' => '<a href="' . admin_url('plugins.php') . '" title="' . __('Goto plugins page') . '" target="_parent">' . __('Return to Plugins page') . '</a>'
-							), array(), $plugin_file);
-		if ( ! empty($install_actions) )
-			show_message('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
-	}
-}
-
-/**
- * Install plugin.
- *
- * @since 2.7.0
- *
- * @param string $package
- * @param string $feedback Optional.
- * @return mixed.
- */
-function wp_install_plugin($package, $feedback = '') {
-	global $wp_filesystem;
-
-	if ( !empty($feedback) )
-		add_filter('install_feedback', $feedback);
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	//Get the base plugin folder
-	$plugins_dir = $wp_filesystem->wp_plugins_dir();
-	if ( empty($plugins_dir) )
-		return new WP_Error('fs_no_plugins_dir', __('Unable to locate WordPress Plugin directory.'));
-
-	//And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress Content directory (wp-content).'));
-
-	$plugins_dir = trailingslashit( $plugins_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	if ( empty($package) )
-		return new WP_Error('no_package', __('Install package not available.'));
-
-	// Download the package
-	apply_filters('install_feedback', sprintf(__('Downloading plugin package from %s'), $package));
-	$download_file = download_url($package);
-
-	if ( is_wp_error($download_file) )
-		return new WP_Error('download_failed', __('Download failed.'), $download_file->get_error_message());
-
-	$working_dir = $content_dir . 'upgrade/' . basename($package, '.zip');
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('install_feedback', __('Unpacking the plugin package'));
-	// Unzip package to working directory
-	$result = unzip_file($download_file, $working_dir);
-
-	// Once extracted, delete the package
-	@unlink($download_file);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	if( $wp_filesystem->exists( $plugins_dir . $filelist[0] ) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('install_folder_exists', __('Folder already exists.'), $filelist[0] );
-	}
-
-	apply_filters('install_feedback', __('Installing the plugin'));
-	// Copy new version of plugin into place.
-	$result = copy_dir($working_dir, $plugins_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	if( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no plugin installed? Failsafe backup.
-
-	$folder = $filelist[0];
-	$plugin = get_plugins('/' . $folder); //Ensure to pass with leading slash
-	$pluginfiles = array_keys($plugin); //Assume the requested plugin is the first in the list
-
-	//Return the plugin files name.
-	return  $folder . '/' . $pluginfiles[0];
-}
-
-/**
- * Install plugin from local package
- *
- * @since 2.7.0
- *
- * @param string $package
- * @param string $feedback Optional.
- * @return mixed.
- */
-function wp_install_plugin_local_package($package, $feedback = '') {
-	global $wp_filesystem;
-
-	if ( !empty($feedback) )
-		add_filter('install_feedback', $feedback);
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	//Get the base plugin folder
-	$plugins_dir = $wp_filesystem->wp_plugins_dir();
-	if ( empty($plugins_dir) )
-		return new WP_Error('fs_no_plugins_dir', __('Unable to locate WordPress Plugin directory.'));
-
-	//And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress Content directory (wp-content).'));
-
-	$plugins_dir = trailingslashit( $plugins_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	if ( empty($package) )
-		return new WP_Error('no_package', __('Install package not available.'));
-
-	$working_dir = $content_dir . 'upgrade/' . basename($package, '.zip');
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('install_feedback', __('Unpacking the plugin package'));
-	// Unzip package to working directory
-	$result = unzip_file($package, $working_dir);
-
-	// Once extracted, delete the package
-	unlink($package);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	if( $wp_filesystem->exists( $plugins_dir . $filelist[0] ) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('install_folder_exists', __('Folder already exists.'), $filelist[0] );
-	}
-
-	apply_filters('install_feedback', __('Installing the plugin'));
-	// Copy new version of plugin into place.
-	$result = copy_dir($working_dir, $plugins_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	if( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no plugin installed? Failsafe backup.
-
-	$folder = $filelist[0];
-	$plugin = get_plugins('/' . $folder); //Ensure to pass with leading slash
-	$pluginfiles = array_keys($plugin); //Assume the requested plugin is the first in the list
-
-	//Return the plugin files name.
-	return  $folder . '/' . $pluginfiles[0];
-}
-
-?>
diff --git a/wp-admin/includes/plugin.php b/wp-admin/includes/plugin.php
index 100ddb0e7a..47daf3df71 100644
--- a/wp-admin/includes/plugin.php
+++ b/wp-admin/includes/plugin.php
@@ -216,6 +216,7 @@ function get_plugins($plugin_folder = '') {
 
 	// Files in wp-content/plugins directory
 	$plugins_dir = @ opendir( $plugin_root);
+	$plugin_files = array();
 	if ( $plugins_dir ) {
 		while (($file = readdir( $plugins_dir ) ) !== false ) {
 			if ( substr($file, 0, 1) == '.' )
@@ -239,7 +240,7 @@ function get_plugins($plugin_folder = '') {
 	@closedir( $plugins_dir );
 	@closedir( $plugins_subdir );
 
-	if ( !$plugins_dir || !$plugin_files )
+	if ( !$plugins_dir || empty($plugin_files) )
 		return $wp_plugins;
 
 	foreach ( $plugin_files as $plugin_file ) {
@@ -432,14 +433,10 @@ function delete_plugins($plugins, $redirect = '' ) {
 		return;
 	}
 
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		return $wp_filesystem->errors;
-	}
-
 	if ( ! is_object($wp_filesystem) )
 		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
 
-	if ( $wp_filesystem->errors->get_error_code() )
+	if ( is_wp_error($wp_filesystem->errors) && $wp_filesystem->errors->get_error_code() )
 		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
 
 	//Get the base plugin folder
diff --git a/wp-admin/includes/theme-install.php b/wp-admin/includes/theme-install.php
index efd53b4f9f..31659517e7 100644
--- a/wp-admin/includes/theme-install.php
+++ b/wp-admin/includes/theme-install.php
@@ -277,12 +277,13 @@ function install_themes_upload($page = 1) {
 ?>
 <h4><?php _e('Install a theme in .zip format') ?></h4>
 <p class="install-help"><?php _e('If you have a theme in a .zip format, you may install it by uploading it here.') ?></p>
-<form method="post" enctype="multipart/form-data" action="<?php echo admin_url('theme-install.php?tab=do_upload') ?>">
+<form method="post" enctype="multipart/form-data" action="<?php echo admin_url('update.php?action=upload-theme') ?>">
 	<?php wp_nonce_field( 'theme-upload') ?>
 	<input type="file" name="themezip" />
-	<input type="submit" class="button" value="<?php _e('Install Now') ?>" />
+	<input type="submit"
+	class="button" value="<?php _e('Install Now') ?>" />
 </form>
-<?php
+	<?php
 }
 
 function display_theme($theme, $actions = null, $show_details = true) {
@@ -411,6 +412,7 @@ function display_themes($themes, $page = 1, $totalpages = 1) {
 	?>
 	<tr>
 	<?php
+
 	foreach ( $cols as $col => $theme_index ) {
 		$class = array('available-theme');
 		if ( $row == 1 ) $class[] = 'top';
@@ -511,7 +513,7 @@ switch ( $type ) {
 default:
 case 'install':
 	if ( current_user_can('install_themes') ) :
-	$buttons .= '<a class="button-primary" id="install" href="' . wp_nonce_url(admin_url('theme-install.php?tab=install&theme=' . $api->slug), 'install-theme_' . $api->slug) . '" target="_parent">' . __('Install Now') . '</a>';
+	$buttons .= '<a class="button-primary" id="install" href="' . wp_nonce_url(admin_url('update.php?action=install-theme&theme=' . $api->slug), 'install-theme_' . $api->slug) . '" target="_parent">' . __('Install Now') . '</a>';
 	endif;
 	break;
 case 'update_available':
@@ -542,365 +544,3 @@ case 'latest_installed':
 	iframe_footer();
 	exit;
 }
-
-add_action('install_themes_do_upload', 'upload_theme');
-function upload_theme() {
-
-	if ( ! ( ( $uploads = wp_upload_dir() ) && false === $uploads['error'] ) )
-		wp_die($uploads['error']);
-
-	if ( !empty($_FILES) )
-		$filename = $_FILES['themezip']['name'];
-	else if ( isset($_GET['package']) )
-		$filename = $_GET['package'];
-
-	check_admin_referer('theme-upload');
-
-	echo '<div class="wrap">';
-	echo '<h2>', sprintf( __('Installing theme from file: %s'), basename($filename) ), '</h2>';
-
-	//Handle a newly uploaded file, Else assume it was
-	if ( !empty($_FILES) ) {
-		$filename = wp_unique_filename( $uploads['basedir'], $filename );
-		$local_file = $uploads['basedir'] . '/' . $filename;
-
-		// Move the file to the uploads dir
-		if ( false === @ move_uploaded_file( $_FILES['themezip']['tmp_name'], $local_file) )
-			wp_die( sprintf( __('The uploaded file could not be moved to %s.' ), $uploads['path']));
-	} else {
-		$local_file = $uploads['basedir'] . '/' . $filename;
-	}
-
-	do_theme_install_local_package($local_file, $filename);
-	echo '</div>';
-}
-
-add_action('install_themes_install', 'install_theme');
-
-/**
- * Display theme link and execute install.
- *
- * @since 2.8.0
- */
-function install_theme() {
-
-	$theme = isset($_REQUEST['theme']) ? stripslashes( $_REQUEST['theme'] ) : '';
-
-	check_admin_referer('install-theme_' . $theme);
-	$api = themes_api('theme_information', array('slug' => $theme, 'fields' => array('sections' => false) ) ); //Save on a bit of bandwidth.
-
-	if ( is_wp_error($api) )
-		wp_die($api);
-
-	echo '<div class="wrap">';
-	echo '<h2>', sprintf( __('Installing theme: %s'), $api->name . ' ' . $api->version ), '</h2>';
-
-	do_theme_install($api->download_link, $api);
-	echo '</div>';
-
-}
-
-/**
- * Retrieve theme and install.
- *
- * @since 2.8.0
- *
- * @param string $download_url Download URL.
- * @param object $theme_information Optional. Theme information
- */
-function do_theme_install($download_url, $theme_information = null) {
-	global $wp_filesystem;
-
-	if ( empty($download_url) ) {
-		show_message( __('No theme specified') );
-		return;
-	}
-
-	$theme        = isset($_REQUEST['theme'])        ? stripslashes( $_REQUEST['theme'] )        : '';
-	$theme_name   = isset($_REQUEST['theme_name'])   ? stripslashes( $_REQUEST['theme_name'] )   : '';
-
-	$url = 'theme-install.php?tab=install';
-	$url = add_query_arg(array('theme' => $theme, 'theme_name' => $theme_name, 'download_url' => $download_url ), $url);
-
-	$url = wp_nonce_url($url, 'install-theme_' . $theme);
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		request_filesystem_credentials($url, '', true); //Failed to connect, Error and request again
-		return;
-	}
-
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-		show_message($message);
-		return;
-	}
-
-	$result = wp_install_theme( $download_url, 'show_message' );
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Installation Failed') );
-	} else {
-		show_message( sprintf(__('Successfully installed the theme <strong>%s %s</strong>.'), $theme_information->name, $theme_information->version) );
-		$theme_file = $result;
-
-		$install_actions = apply_filters('install_theme_complete_actions', array(
-		//'activate_theme' => '<a href="' . wp_nonce_url('themes.php?action=activate&amp;theme=' . $theme_file, 'activate-theme_' . $theme_file) . '" title="' . attribute_escape(__('Activate this theme')) . '" target="_parent">' . __('Activate Theme') . '</a>',
-			'themes_page' => '<a href="' . admin_url('themes.php') . '" title="' . attribute_escape(__('Return to Themes page')) . '" target="_parent">' . __('Return to Themes page') . '</a>'
-			), $theme_information, $theme_file);
-			if ( ! empty($install_actions) )
-			show_message('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
-	}
-}
-
-/**
- * Install a theme from a local file.
- *
- * @since 2.8.0
- *
- * @param string $package Local Theme zip
- * @param string $filename Optional. Original filename
- * @param object $theme_information Optional. Theme information
- */
-function do_theme_install_local_package($package, $filename = '') {
-	global $wp_filesystem;
-
-	if ( empty($package) ) {
-		show_message( __('No theme specified') );
-		return;
-	}
-
-	if ( empty($filename) )
-		$filename = basename($package);
-
-	$url = 'theme-install.php?tab=upload';
-	$url = add_query_arg(array('package' => $filename), $url);
-
-	$url = wp_nonce_url($url, 'theme-upload');
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		request_filesystem_credentials($url, '', true); //Failed to connect, Error and request again
-		return;
-	}
-
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-		show_message($message);
-		return;
-	}
-
-	$result = wp_install_theme_local_package( $package, 'show_message' );
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Installation Failed') );
-	} else {
-		show_message( __('Successfully installed the theme.') );
-		$theme_file = $result;
-
-		$install_actions = apply_filters('install_theme_complete_actions', array(
-		//'activate_theme' => '<a href="' . wp_nonce_url('themes.php?action=activate&amp;theme=' . $theme_file, 'activate-theme_' . $theme_file) . '" title="' . __('Activate this theme') . '" target="_parent">' . __('Activate Theme') . '</a>',
-							'themes_page' => '<a href="' . admin_url('themes.php') . '" title="' . __('Goto themes page') . '" target="_parent">' . __('Return to Themes page') . '</a>'
-							), array(), $theme_file);
-							if ( ! empty($install_actions) )
-							show_message('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$install_actions));
-	}
-}
-
-/**
- * Install theme.
- *
- * @since 2.8.0
- *
- * @param string $package
- * @param string $feedback Optional.
- * @return mixed.
- */
-function wp_install_theme($package, $feedback = '') {
-	global $wp_filesystem;
-
-	if ( !empty($feedback) )
-		add_filter('install_feedback', $feedback);
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	// Get the base theme folder
-	$themes_dir = $wp_filesystem->wp_themes_dir();
-	if ( empty($themes_dir) )
-		return new WP_Error('fs_no_themes_dir', __('Unable to locate WordPress themes directory.'));
-
-	// And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if ( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress content directory (wp-content).'));
-
-	$themes_dir = trailingslashit( $themes_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	if ( empty($package) )
-		return new WP_Error('no_package', __('Install package not available.'));
-
-	// Download the package
-	apply_filters('install_feedback', sprintf(__('Downloading theme package from %s'), $package));
-	$download_file = download_url($package);
-
-	if ( is_wp_error($download_file) )
-		return new WP_Error('download_failed', __('Download failed.'), $download_file->get_error_message());
-
-	$working_dir = $content_dir . 'upgrade/' . basename($package, '.zip');
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('install_feedback', __('Unpacking the theme package'));
-	// Unzip package to working directory
-	$result = unzip_file($download_file, $working_dir);
-
-	// Once extracted, delete the package
-	@unlink($download_file);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the theme
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	if ( $wp_filesystem->exists( $themes_dir . $filelist[0] ) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('install_folder_exists', __('Folder already exists.'), $filelist[0] );
-	}
-
-	apply_filters('install_feedback', __('Installing the theme'));
-	// Copy new version of theme into place.
-	$result = copy_dir($working_dir, $themes_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the theme
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	if ( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no theme installed? Failsafe backup.
-
-	//TODO: TODO: TODO
-	$stylesheet = $filelist[0];
-	//	$theme = get_themes('/' . $folder); //Ensure to pass with leading slash //TODO: TODO: TODO
-	//	$themefiles = array_keys($theme); //Assume the requested theme is the first in the list
-
-	//Return the theme files name.
-	return  $stylesheet; //$folder . '/' . $themefiles[0];
-}
-
-/**
- * Install theme from local package
- *
- * @since 2.8.0
- *
- * @param string $package
- * @param string $feedback Optional.
- * @return mixed.
- */
-function wp_install_theme_local_package($package, $feedback = '') {
-	global $wp_filesystem;
-
-	if ( !empty($feedback) )
-		add_filter('install_feedback', $feedback);
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	//Get the base theme folder
-	$themes_dir = $wp_filesystem->wp_themes_dir();
-	if ( empty($themes_dir) )
-		return new WP_Error('fs_no_themes_dir', __('Unable to locate WordPress themes directory.'));
-
-	//And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if ( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress content directory (wp-content).'));
-
-	$themes_dir = trailingslashit( $themes_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	if ( empty($package) )
-		return new WP_Error('no_package', __('Install package not available.'));
-
-	$working_dir = $content_dir . 'upgrade/' . basename($package, '.zip');
-
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('install_feedback', __('Unpacking the theme package'));
-	// Unzip package to working directory
-	$result = unzip_file($package, $working_dir);
-
-	// Once extracted, delete the package
-	unlink($package);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the theme
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	if ( $wp_filesystem->exists( $themes_dir . $filelist[0] ) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('install_folder_exists', __('Folder already exists.'), $filelist[0] );
-	}
-
-	apply_filters('install_feedback', __('Installing the theme'));
-	// Copy new version of theme into place.
-	$result = copy_dir($working_dir, $themes_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the theme
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	if ( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no theme installed? Failsafe backup.
-
-	//TODO TODO TODO
-	$stylesheet = $filelist[0];
-	//	$theme = get_themes('/' . $folder); //Ensure to pass with leading slash
-	//	$themefiles = array_keys($theme); //Assume the requested theme is the first in the list
-
-	//Return the theme files name.
-	return  $stylsheet; //$folder . '/' . $themefiles[0];
-}
diff --git a/wp-admin/includes/theme.php b/wp-admin/includes/theme.php
index da67051b90..abdd8ddd54 100644
--- a/wp-admin/includes/theme.php
+++ b/wp-admin/includes/theme.php
@@ -72,14 +72,11 @@ function delete_theme($template) {
 		return;
 	}
 
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		return $wp_filesystem->errors;
-	}
 
 	if ( ! is_object($wp_filesystem) )
 		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
 
-	if ( $wp_filesystem->errors->get_error_code() )
+	if ( is_wp_error($wp_filesystem->errors) && $wp_filesystem->errors->get_error_code() )
 		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
 
 	//Get the base plugin folder
diff --git a/wp-admin/includes/update-core.php b/wp-admin/includes/update-core.php
index 038e77cb74..2e2b303bbd 100644
--- a/wp-admin/includes/update-core.php
+++ b/wp-admin/includes/update-core.php
@@ -229,7 +229,7 @@ function update_core($from, $to) {
 	$result = copy_dir($from . '/wordpress', $to);
 	if ( is_wp_error($result) ) {
 		$wp_filesystem->delete($maintenance_file);
-		//$wp_filesystem->delete($working_dir, true); //TODO: Uncomment? This DOES mean that the new files are available in the upgrade folder if it fails.
+		$wp_filesystem->delete($working_dir, true);
 		return $result;
 	}
 
diff --git a/wp-admin/includes/update.php b/wp-admin/includes/update.php
index 26ff3744a8..a09f815297 100644
--- a/wp-admin/includes/update.php
+++ b/wp-admin/includes/update.php
@@ -167,312 +167,35 @@ function wp_plugin_update_row( $file, $plugin_data ) {
 add_action( 'after_plugin_row', 'wp_plugin_update_row', 10, 2 );
 
 function wp_update_plugin($plugin, $feedback = '') {
-	global $wp_filesystem;
 
 	if ( !empty($feedback) )
 		add_filter('update_feedback', $feedback);
 
-	// Is an update available?
-	$current = get_transient( 'update_plugins' );
-	if ( !isset( $current->response[ $plugin ] ) )
-		return new WP_Error('up_to_date', __('The plugin is at the latest version.'));
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	//Get the base plugin folder
-	$plugins_dir = $wp_filesystem->wp_plugins_dir();
-	if ( empty($plugins_dir) )
-		return new WP_Error('fs_no_plugins_dir', __('Unable to locate WordPress Plugin directory.'));
-
-	//And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress Content directory (wp-content).'));
-
-	$plugins_dir = trailingslashit( $plugins_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	// Get the URL to the zip file
-	$r = $current->response[ $plugin ];
-
-	if ( empty($r->package) )
-		return new WP_Error('no_package', __('Upgrade package not available.'));
-
-	// Download the package
-	$package = $r->package;
-	apply_filters('update_feedback', sprintf(__('Downloading update from %s'), $package));
-	$download_file = download_url($package);
-
-	if ( is_wp_error($download_file) )
-		return new WP_Error('download_failed', __('Download failed.'), $download_file->get_error_message());
-
-	$working_dir = $content_dir . 'upgrade/' . basename($plugin, '.php');
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('update_feedback', __('Unpacking the update'));
-	// Unzip package to working directory
-	$result = unzip_file($download_file, $working_dir);
-
-	// Once extracted, delete the package
-	unlink($download_file);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	if ( is_plugin_active($plugin) ) {
-		//Deactivate the plugin silently, Prevent deactivation hooks from running.
-		apply_filters('update_feedback', __('Deactivating the plugin'));
-		deactivate_plugins($plugin, true);
-	}
-
-	// Remove the existing plugin.
-	apply_filters('update_feedback', __('Removing the old version of the plugin'));
-	$this_plugin_dir = trailingslashit( dirname($plugins_dir . $plugin) );
-
-	// If plugin is in its own directory, recursively delete the directory.
-	if ( strpos($plugin, '/') && $this_plugin_dir != $plugins_dir ) //base check on if plugin includes directory seperator AND that its not the root plugin folder
-		$deleted = $wp_filesystem->delete($this_plugin_dir, true);
-	else
-		$deleted = $wp_filesystem->delete($plugins_dir . $plugin);
-
-	if ( ! $deleted ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('delete_failed', __('Could not remove the old plugin'));
-	}
-
-	apply_filters('update_feedback', __('Installing the latest version'));
-	// Copy new version of plugin into place.
-	$result = copy_dir($working_dir, $plugins_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	// Force refresh of plugin update information
-	delete_transient('update_plugins');
-
-	if( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no plugin installed? Failsafe backup.
-
-	$folder = $filelist[0];
-	$plugin = get_plugins('/' . $folder); //Ensure to pass with leading slash
-	$pluginfiles = array_keys($plugin); //Assume the requested plugin is the first in the list
-
-	return  $folder . '/' . $pluginfiles[0];
+	include ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
+	$upgrader = new Plugin_Upgrader();
+	return $upgrader->upgrade($plugin);
 }
 
 function wp_update_theme($theme, $feedback = '') {
-	global $wp_filesystem;
-
+	
 	if ( !empty($feedback) )
 		add_filter('update_feedback', $feedback);
 
-	// Is an update available?
-	$current = get_transient( 'update_themes' );
-	if ( !isset( $current->response[ $theme ] ) )
-		return new WP_Error('up_to_date', __('The theme is at the latest version.'));
-
-	$r = $current->response[ $theme ];
-
-	$themes = get_themes();
-	foreach ( (array) $themes as $this_theme ) {
-		if ( $this_theme['Stylesheet'] == $theme ) {
-			$theme_directory = preg_replace('!^/themes/!i', '', $this_theme['Stylesheet Dir']);
-			break;
-		}
-	}
-	unset($themes);
-
-	if ( empty($theme_directory) )
-		return new WP_Error('theme_non_existant', __('Theme does not exist.'));
-
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	//Get the base plugin folder
-	$themes_dir = $wp_filesystem->wp_themes_dir();
-	if ( empty($themes_dir) )
-		return new WP_Error('fs_no_themes_dir', __('Unable to locate WordPress Theme directory.'));
-
-	//And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress Content directory (wp-content).'));
-
-	$themes_dir = trailingslashit( $themes_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	if ( empty($r->package) )
-		return new WP_Error('no_package', __('Upgrade package not available.'));
-
-	// Download the package
-	apply_filters('update_feedback', sprintf(__('Downloading update from %s'), $r['package']));
-	$download_file = download_url($r['package']);
-
-	if ( is_wp_error($download_file) )
-		return new WP_Error('download_failed', __('Download failed.'), $download_file->get_error_message());
-
-	$working_dir = $content_dir . 'upgrade/' . basename($theme_directory);
-
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) )
-		$wp_filesystem->delete($working_dir, true);
-
-	apply_filters('update_feedback', __('Unpacking the update'));
-	// Unzip package to working directory
-	$result = unzip_file($download_file, $working_dir);
-
-	// Once extracted, delete the package
-	unlink($download_file);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//TODO: Is theme currently active? If so, set default theme
-	/*
-	if ( is_plugin_active($plugin) ) {
-		//Deactivate the plugin silently, Prevent deactivation hooks from running.
-		apply_filters('update_feedback', __('Deactivating the plugin'));
-		deactivate_plugins($plugin, true);
-	}*/
-
-	// Remove the existing plugin.
-	apply_filters('update_feedback', __('Removing the old version of the theme'));
-	$deleted = $wp_filesystem->delete($themes_dir . $theme_directory, true);
-
-	if ( ! $deleted ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('delete_failed', __('Could not remove the old plugin'));
-	}
-
-	apply_filters('update_feedback', __('Installing the latest version'));
-	// Copy new version of plugin into place.
-	$result = copy_dir($working_dir, $themes_dir);
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	//Get a list of the directories in the working directory before we delete it, We need to know the new folder for the plugin
-	//$filelist = array_keys( $wp_filesystem->dirlist($working_dir) );
-
-	// Remove working directory
-	$wp_filesystem->delete($working_dir, true);
-
-	// Force refresh of plugin update information
-	delete_transient('update_themes');
-
-	/*if( empty($filelist) )
-		return false; //We couldnt find any files in the working dir, therefor no plugin installed? Failsafe backup.
-
-	$folder = $filelist[0];
-	$plugin = get_plugins('/' . $folder); //Ensure to pass with leading slash
-	$pluginfiles = array_keys($plugin); //Assume the requested plugin is the first in the list
-
-	return  $folder . '/' . $pluginfiles[0];*/
+	include ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
+	$upgrader = new Theme_Upgrader();
+	return $upgrader->upgrade($theme);
 }
 
 
 function wp_update_core($current, $feedback = '') {
-	global $wp_filesystem;
-
-	@set_time_limit( 300 );
-
+	
 	if ( !empty($feedback) )
 		add_filter('update_feedback', $feedback);
 
-	// Is an update available?
-	if ( !isset( $current->response ) || $current->response == 'latest' )
-		return new WP_Error('up_to_date', __('WordPress is at the latest version.'));
+	include ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
+	$upgrader = new Core_Upgrader();
+	return $upgrader->upgrade($current);
 
-	// Is a filesystem accessor setup?
-	if ( ! $wp_filesystem || ! is_object($wp_filesystem) )
-		WP_Filesystem();
-
-	if ( ! is_object($wp_filesystem) )
-		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));
-
-	if ( $wp_filesystem->errors->get_error_code() )
-		return new WP_Error('fs_error', __('Filesystem error'), $wp_filesystem->errors);
-
-	// Get the base WP folder
-	$wp_dir = $wp_filesystem->abspath();
-	if ( empty($wp_dir) )
-		return new WP_Error('fs_no_wp_dir', __('Unable to locate WordPress directory.'));
-
-	// And the same for the Content directory.
-	$content_dir = $wp_filesystem->wp_content_dir();
-	if( empty($content_dir) )
-		return new WP_Error('fs_no_content_dir', __('Unable to locate WordPress Content directory (wp-content).'));
-
-	$wp_dir = trailingslashit( $wp_dir );
-	$content_dir = trailingslashit( $content_dir );
-
-	// Get the URL to the zip file
-	$package = $current->package;
-
-	// Download the package
-	apply_filters('update_feedback', sprintf(__('Downloading update from %s'), $package));
-	$download_file = download_url($package);
-
-	if ( is_wp_error($download_file) )
-		return new WP_Error('download_failed', __('Download failed.'), $download_file->get_error_message());
-
-	$working_dir = $content_dir . 'upgrade/core';
-	// Clean up working directory
-	if ( $wp_filesystem->is_dir($working_dir) ) {
-		$wp_filesystem->delete($working_dir, true);
-	}
-
-	apply_filters('update_feedback', __('Unpacking the core update'));
-	// Unzip package to working directory
-	$result = unzip_file($download_file, $working_dir);
-	// Once extracted, delete the package
-	unlink($download_file);
-
-	if ( is_wp_error($result) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return $result;
-	}
-
-	// Copy update-core.php from the new version into place.
-	if ( !$wp_filesystem->copy($working_dir . '/wordpress/wp-admin/includes/update-core.php', $wp_dir . 'wp-admin/includes/update-core.php', true) ) {
-		$wp_filesystem->delete($working_dir, true);
-		return new WP_Error('copy_failed', __('Could not copy files'));
-	}
-	$wp_filesystem->chmod($wp_dir . 'wp-admin/includes/update-core.php', FS_CHMOD_FILE);
-
-	require(ABSPATH . 'wp-admin/includes/update-core.php');
-
-	return update_core($working_dir, $wp_dir);
 }
 
 function maintenance_nag() {
diff --git a/wp-admin/plugin-install.php b/wp-admin/plugin-install.php
index 03995cede4..75a3de4378 100644
--- a/wp-admin/plugin-install.php
+++ b/wp-admin/plugin-install.php
@@ -24,7 +24,7 @@ add_thickbox();
 
 //These are the tabs which are shown on the page,
 $tabs = array();
-$tabs['dashboard'] = __('Search'); //TODO: Better name?
+$tabs['dashboard'] = __('Search');
 if ( 'search' == $tab )
 	$tabs['search']	= __('Search Results');
 $tabs['upload'] = __('Upload');
@@ -33,7 +33,7 @@ $tabs['popular']  = __('Popular');
 $tabs['new']      = __('Newest');
 $tabs['updated']  = __('Recently Updated');
 
-$nonmenu_tabs = array('install', 'plugin-information', 'do_upload'); //Valid actions to perform which do not have a Menu item.
+$nonmenu_tabs = array('plugin-information'); //Valid actions to perform which do not have a Menu item.
 
 $tabs = apply_filters('install_plugins_tabs', $tabs );
 $nonmenu_tabs = apply_filters('install_plugins_nonmenu_tabs', $nonmenu_tabs);
@@ -62,7 +62,7 @@ $display_tabs = array();
 foreach ( (array)$tabs as $action => $text ) {
 	$sep = ( end($tabs) != $text ) ? ' | ' : '';
 	$class = ( $action == $tab ) ? ' class="current"' : '';
-	$href = admin_url('plugin-install.php?tab='. $action);
+	$href = admin_url('plugin-install.php?tab=' . $action);
 	echo "\t\t<li><a href='$href'$class>$text</a>$sep</li>\n";
 }
 ?>
@@ -71,5 +71,4 @@ foreach ( (array)$tabs as $action => $text ) {
 	<?php do_action('install_plugins_' . $tab, $paged); ?>
 </div>
 <?php
-include('admin-footer.php');
-?>
+include('admin-footer.php');
\ No newline at end of file
diff --git a/wp-admin/theme-install.php b/wp-admin/theme-install.php
index 4255d630a7..480bec304f 100644
--- a/wp-admin/theme-install.php
+++ b/wp-admin/theme-install.php
@@ -35,7 +35,7 @@ $tabs['featured'] = __('Featured');
 $tabs['new']      = __('Newest');
 $tabs['updated']  = __('Recently Updated');
 
-$nonmenu_tabs = array('install', 'theme-information', 'do_upload'); //Valid actions to perform which do not have a Menu item.
+$nonmenu_tabs = array('theme-information'); //Valid actions to perform which do not have a Menu item.
 
 $tabs = apply_filters('install_themes_tabs', $tabs );
 $nonmenu_tabs = apply_filters('install_themes_nonmenu_tabs', $nonmenu_tabs);
diff --git a/wp-admin/update.php b/wp-admin/update.php
index 8a39aedb13..44bdb5a4b7 100644
--- a/wp-admin/update.php
+++ b/wp-admin/update.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Update Plugin/Theme administration panel.
+ * Update/Install Plugin/Theme administration panel.
  *
  * @package WordPress
  * @subpackage Administration
@@ -9,134 +9,36 @@
 /** WordPress Administration Bootstrap */
 require_once('admin.php');
 
-if ( ! current_user_can('update_plugins') )
-	wp_die(__('You do not have sufficient permissions to update plugins for this blog.'));
-
-/**
- * Plugin upgrade display.
- *
- * @since 2.5
- *
- * @param string $plugin Plugin
- */
-function do_plugin_upgrade($plugin) {
-	global $wp_filesystem;
-
-	$url = wp_nonce_url("update.php?action=upgrade-plugin&plugin=$plugin", "upgrade-plugin_$plugin");
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		$error = true;
-		if ( is_object($wp_filesystem) && $wp_filesystem->errors->get_error_code() )
-			$error = $wp_filesystem->errors;
-		request_filesystem_credentials($url, '', $error); //Failed to connect, Error and request again
-		return;
-	}
-
-	echo '<div class="wrap">';
-	echo screen_icon();
-	echo '<h2>' . __('Upgrade Plugin') . '</h2>';
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-			show_message($message);
-		echo '</div>';
-		return;
-	}
-
-	$was_activated = is_plugin_active($plugin); //Check now, It'll be deactivated by the next line if it is
-
-	$result = wp_update_plugin($plugin, 'show_message');
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Plugin upgrade Failed') );
-	} else {
-		$plugin_file = $result;
-		show_message( __('Plugin upgraded successfully') );
-		if( $result && $was_activated ){
-			show_message(__('Attempting reactivation of the plugin'));
-			echo '<iframe style="border:0;overflow:hidden" width="100%" height="170px" src="' . wp_nonce_url('update.php?action=activate-plugin&plugin=' . $plugin_file, 'activate-plugin_' . $plugin_file) .'"></iframe>';
-		}
-		$update_actions =  array(
-			'activate_plugin' => '<a href="' . wp_nonce_url('plugins.php?action=activate&amp;plugin=' . $plugin_file, 'activate-plugin_' . $plugin_file) . '" title="' . attribute_escape(__('Activate this plugin')) . '" target="_parent">' . __('Activate Plugin') . '</a>',
-			'plugins_page' => '<a href="' . admin_url('plugins.php') . '" title="' . attribute_escape(__('Goto plugins page')) . '" target="_parent">' . __('Return to Plugins page') . '</a>'
-		);
-		if ( $was_activated )
-			unset( $update_actions['activate_plugin'] );
-
-		$update_actions = apply_filters('update_plugin_complete_actions', $update_actions, $plugin_file);
-		if ( ! empty($update_actions) )
-			show_message('<strong>' . __('Actions:') . '</strong> ' . implode(' | ', (array)$update_actions));
-	}
-	echo '</div>';
-}
-
-/**
- * Theme upgrade display.
- *
- * @since 2.5
- *
- * @param string $plugin Plugin
- */
-function do_theme_upgrade($theme) {
-	global $wp_filesystem;
-
-	$url = wp_nonce_url('update.php?action=upgrade-theme&theme=' . urlencode($theme), 'upgrade-theme_' . urlencode($theme));
-	if ( false === ($credentials = request_filesystem_credentials($url)) )
-		return;
-
-	if ( ! WP_Filesystem($credentials) ) {
-		$error = true;
-		if ( is_object($wp_filesystem) && $wp_filesystem->errors->get_error_code() )
-			$error = $wp_filesystem->errors;
-		request_filesystem_credentials($url, '', $error); //Failed to connect, Error and request again
-		return;
-	}
-
-	echo '<div class="wrap">';
-	echo screen_icon();
-	echo '<h2>' . __('Upgrade Theme') . '</h2>';
-	if ( $wp_filesystem->errors->get_error_code() ) {
-		foreach ( $wp_filesystem->errors->get_error_messages() as $message )
-			show_message($message);
-		echo '</div>';
-		return;
-	}
-
-	//TODO: Is theme currently active?
-	$was_current = false; //is_plugin_active($plugin); //Check now, It'll be deactivated by the next line if it is
-
-	$result = wp_update_theme($theme, 'show_message');
-
-	if ( is_wp_error($result) ) {
-		show_message($result);
-		show_message( __('Installation Failed') );
-	} else {
-		//Result is the new plugin file relative to WP_PLUGIN_DIR
-		show_message( __('Theme upgraded successfully') );
-		if( $result && $was_current ){
-			show_message(__('Setting theme as Current'));
-			//TODO: Actually set it as active again.
-			//echo '<iframe style="border:0" width="100%" height="170px" src="' . wp_nonce_url('update.php?action=activate-plugin&plugin=' . $result, 'activate-plugin_' . $result) .'"></iframe>';
-		}
-	}
-	echo '</div>';
-}
+include_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
 
 if ( isset($_GET['action']) ) {
-	$plugin = isset($_GET['plugin']) ? trim($_GET['plugin']) : '';
+	$plugin = isset($_REQUEST['plugin']) ? trim($_REQUEST['plugin']) : '';
 	$theme = isset($_REQUEST['theme']) ? urldecode($_REQUEST['theme']) : '';
-	$action = isset($_GET['action']) ? $_GET['action'] : '';
+	$action = isset($_REQUEST['action']) ? $_REQUEST['action'] : '';
 
 	if ( 'upgrade-plugin' == $action ) {
+		if ( ! current_user_can('update_plugins') )
+			wp_die(__('You do not have sufficient permissions to update plugins for this blog.'));
+
 		check_admin_referer('upgrade-plugin_' . $plugin);
+
 		$title = __('Upgrade Plugin');
 		$parent_file = 'plugins.php';
+		$submenu_file = 'plugins.php';
 		require_once('admin-header.php');
-		do_plugin_upgrade($plugin);
+
+		$nonce = 'upgrade-plugin_' . $plugin;
+		$url = 'update.php?action=upgrade-plugin&plugin=' . $plugin;
+
+		$upgrader = new Plugin_Upgrader( new Plugin_Upgrader_Skin( compact('title', 'nonce', 'url', 'plugin') ) );
+		$upgrader->upgrade($plugin);
+
 		include('admin-footer.php');
+		
 	} elseif ('activate-plugin' == $action ) {
+		if ( ! current_user_can('update_plugins') )
+			wp_die(__('You do not have sufficient permissions to update plugins for this blog.'));
+
 		check_admin_referer('activate-plugin_' . $plugin);
 		if( ! isset($_GET['failure']) && ! isset($_GET['success']) ) {
 			wp_redirect( 'update.php?action=activate-plugin&failure=true&plugin=' . $plugin . '&_wpnonce=' . $_GET['_wpnonce'] );
@@ -155,14 +57,145 @@ if ( isset($_GET['action']) ) {
 			include(WP_PLUGIN_DIR . '/' . $plugin);
 		}
 		iframe_footer();
+	} elseif ( 'install-plugin' == $action ) {
+
+		if ( ! current_user_can('install_plugins') )
+			wp_die(__('You do not have sufficient permissions to install plugins for this blog.'));
+
+		include_once ABSPATH . 'wp-admin/includes/plugin-install.php'; //for plugins_api..
+	
+		check_admin_referer('install-plugin_' . $plugin);
+		$api = plugins_api('plugin_information', array('slug' => $plugin, 'fields' => array('sections' => false) ) ); //Save on a bit of bandwidth.
+	
+		if ( is_wp_error($api) )
+	 		wp_die($api);
+	
+		$title = __('Plugin Install');
+		$parent_file = 'plugins.php';
+		$submenu_file = 'plugin-install.php';
+		require_once('admin-header.php');
+	
+		$title = sprintf( __('Installing Plugin: %s'), $api->name . ' ' . $api->version );
+		$nonce = 'install-plugin_' . $plugin;
+		$url = add_query_arg( array(
+								'plugin' => $plugin,
+								'plugin_name' => $api->name . ' ' . $api->version,
+								'download_url' => $api->download_link
+							), 'update.php?action=install-plugin');
+		$type = 'web'; //Install plugin type, From Web or an Upload.
+
+		$upgrader = new Plugin_Upgrader( new Plugin_Installer_Skin( compact('title', 'url', 'nonce', 'plugin', 'api') ) );
+		$upgrader->install($api->download_link);
+		
+		include('admin-footer.php');
+
+	} elseif ( 'upload-plugin' == $action ) {
+
+		if ( ! current_user_can('install_plugins') )
+			wp_die(__('You do not have sufficient permissions to install plugins for this blog.'));
+
+		check_admin_referer('plugin-upload');
+
+		$file_upload = new File_Upload_Upgrader('pluginzip', 'package');
+
+		$title = __('Upload Plugin');
+		$parent_file = 'plugins.php';
+		$submenu_file = 'plugin-install.php';
+		require_once('admin-header.php');
+		
+		$title = sprintf( __('Installing Plugin from uploaded file: %s'), basename( $file_upload->filename ) );
+		$nonce = 'plugin-upload';
+		$url = add_query_arg(array('package' => $file_upload->filename ), 'update.php?action=upload-plugin');
+		$type = 'upload'; //Install plugin type, From Web or an Upload.
+
+		$upgrader = new Plugin_Upgrader( new Plugin_Installer_Skin( compact('type', 'title', 'nonce', 'url') ) );
+		$upgrader->install( $file_upload->package );
+
+		include('admin-footer.php');
+
 	} elseif ( 'upgrade-theme' == $action ) {
+
+		if ( ! current_user_can('update_themes') )
+			wp_die(__('You do not have sufficient permissions to update themes for this blog.'));
+
 		check_admin_referer('upgrade-theme_' . $theme);
+
+		add_thickbox();
+		wp_enqueue_script('theme-preview');
 		$title = __('Upgrade Theme');
 		$parent_file = 'themes.php';
+		$submenu_file = 'themes.php';
 		require_once('admin-header.php');
-		do_theme_upgrade($theme);
-		include('admin-footer.php');
-	}
-}
 
-?>
+		$nonce = 'upgrade-theme_' . $theme;
+		$url = 'update.php?action=upgrade-theme&theme=' . $theme;
+
+		$upgrader = new Theme_Upgrader( new Theme_Upgrader_Skin( compact('title', 'nonce', 'url', 'theme') ) );
+		$upgrader->upgrade($theme);
+
+		include('admin-footer.php');
+	
+	} elseif ( 'install-theme' == $action ) {
+
+		if ( ! current_user_can('install_themes') )
+			wp_die(__('You do not have sufficient permissions to install themes for this blog.'));
+
+		include_once ABSPATH . 'wp-admin/includes/theme-install.php'; //for themes_api..
+	
+		check_admin_referer('install-theme_' . $theme);
+		$api = themes_api('theme_information', array('slug' => $theme, 'fields' => array('sections' => false) ) ); //Save on a bit of bandwidth.
+
+		if ( is_wp_error($api) )
+	 		wp_die($api);
+
+		add_thickbox();
+		wp_enqueue_script('theme-preview');
+		$title = __('Install Themes');
+		$parent_file = 'themes.php';
+		$submenu_file = 'theme-install.php';
+		require_once('admin-header.php');
+	
+		$title = sprintf( __('Installing theme: %s'), $api->name . ' ' . $api->version );
+		$nonce = 'install-theme_' . $theme;
+		$url = add_query_arg( array(
+								'theme' => $theme,
+								'theme_name' => $api->name . ' ' . $api->version,
+								'download_url' => $api->download_link
+							), 'update.php?action=install-theme');
+		$type = 'web'; //Install theme type, From Web or an Upload.
+	
+		$upgrader = new Theme_Upgrader( new Theme_Installer_Skin( compact('title', 'url', 'nonce', 'plugin', 'api') ) );
+		$upgrader->install($api->download_link);
+		
+		include('admin-footer.php');
+		
+	} elseif ( 'upload-theme' == $action ) {
+
+		if ( ! current_user_can('install_themes') )
+			wp_die(__('You do not have sufficient permissions to install themes for this blog.'));
+
+		check_admin_referer('theme-upload');
+
+		$file_upload = new File_Upload_Upgrader('themezip', 'package');
+
+		$title = __('Upload Theme');
+		$parent_file = 'themes.php';
+		$submenu_file = 'theme-install.php';
+		add_thickbox();
+		wp_enqueue_script('theme-preview');
+		require_once('admin-header.php');
+
+		$title = sprintf( __('Installing Theme from uploaded file: %s'), basename( $file_upload->filename ) );
+		$nonce = 'theme-upload';
+		$url = add_query_arg(array('package' => $file_upload->filename), 'update.php?action=upload-theme');
+		$type = 'upload'; //Install plugin type, From Web or an Upload.
+
+		$upgrader = new Theme_Upgrader( new Theme_Installer_Skin( compact('type', 'title', 'nonce', 'url') ) );
+		$upgrader->install( $file_upload->package );
+
+		include('admin-footer.php');
+
+	} else {
+		do_action('update-custom_' . $action);
+	}
+}
\ No newline at end of file