diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index d9060ceb94..ad2fdae669 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -45,7 +45,7 @@ $core_actions_post = array(
 	'menu-locations-save', 'menu-quick-search', 'meta-box-order', 'get-permalink',
 	'sample-permalink', 'inline-save', 'inline-save-tax', 'find_posts', 'widgets-order',
 	'save-widget', 'set-post-thumbnail', 'date_format', 'time_format', 'wp-fullscreen-save-post',
-	'wp-remove-post-lock', 'dismiss-wp-pointer',
+	'wp-remove-post-lock', 'dismiss-wp-pointer', 'upload-attachment',
 );
 
 // Register core Ajax calls.
diff --git a/wp-admin/includes/ajax-actions.php b/wp-admin/includes/ajax-actions.php
index 93d1b4a848..be77857844 100644
--- a/wp-admin/includes/ajax-actions.php
+++ b/wp-admin/includes/ajax-actions.php
@@ -1544,6 +1544,50 @@ function wp_ajax_save_widget() {
 	wp_die();
 }
 
+function wp_ajax_upload_attachment() {
+	check_ajax_referer( 'media-form' );
+
+	if ( ! current_user_can( 'upload_files' ) )
+		wp_die( -1 );
+
+	if ( isset( $_REQUEST['post_id'] ) ) {
+		$post_id = $_REQUEST['post_id'];
+		if ( ! current_user_can( 'edit_post', $post_id ) )
+			wp_die( -1 );
+	} else {
+		$post_id = null;
+	}
+
+	$post_data = is_array( $_REQUEST['post_data'] ) ? $_REQUEST['post_data'] : array();
+
+	$attachment_id = media_handle_upload( 'async-upload', $post_id, $post_data );
+
+	if ( is_wp_error( $attachment_id ) ) {
+		echo json_encode( array(
+			'type' => 'error',
+			'data' => array(
+				'message'  => $attachment_id->get_error_message(),
+				'filename' => $_FILES['async-upload']['name'],
+			),
+		) );
+		wp_die();
+	}
+
+	$post = get_post( $attachment_id );
+
+	echo json_encode( array(
+		'type' => 'success',
+		'data' => array(
+			'id'       => $attachment_id,
+			'title'    => esc_attr( $post->post_title ),
+			'filename' => esc_html( basename( $post->guid ) ),
+			'url'      => wp_get_attachment_url( $attachment_id ),
+			'meta'     => wp_get_attachment_metadata( $attachment_id ),
+		),
+	) );
+	wp_die();
+}
+
 function wp_ajax_image_editor() {
 	$attachment_id = intval($_POST['postid']);
 	if ( empty($attachment_id) || !current_user_can('edit_post', $attachment_id) )
diff --git a/wp-includes/class-wp-customize-setting.php b/wp-includes/class-wp-customize-setting.php
index 710026c221..54b1eac7a7 100644
--- a/wp-includes/class-wp-customize-setting.php
+++ b/wp-includes/class-wp-customize-setting.php
@@ -70,6 +70,9 @@ class WP_Customize_Setting {
 				wp_enqueue_script( 'farbtastic' );
 				wp_enqueue_style( 'farbtastic' );
 				break;
+			case 'upload':
+				wp_enqueue_script( 'wp-plupload' );
+				break;
 		}
 	}
 
@@ -394,6 +397,15 @@ class WP_Customize_Setting {
 				</select>
 				<?php
 				break;
+			case 'upload':
+				?>
+				<label><?php echo esc_html( $this->label ); ?><br/>
+					<input type="hidden" value="<?php echo esc_attr( $this->value() ); ?>" <?php $this->name(); ?> />
+					<a href="#" class="button-secondary upload"><?php _e( 'Upload' ); ?></a>
+					<a href="#" class="remove"><?php _e( 'Remove' ); ?></a>
+				</label>
+				<?php
+				break;
 			default:
 				do_action( 'customize_render_control-' . $this->control, $this );
 
diff --git a/wp-includes/class-wp-customize.php b/wp-includes/class-wp-customize.php
index 68576c5011..1763a7f282 100644
--- a/wp-includes/class-wp-customize.php
+++ b/wp-includes/class-wp-customize.php
@@ -523,7 +523,13 @@ final class WP_Customize {
 			'section'           => 'background',
 			'control'           => 'color',
 			'default'           => defined( 'BACKGROUND_COLOR' ) ? BACKGROUND_COLOR : '',
-			'sanitize_callback' => 'sanitize_hexcolor'
+			'sanitize_callback' => 'sanitize_hexcolor',
+		) );
+
+		$this->add_setting( 'background_image', array(
+			'label'             => 'Background Image',
+			'section'           => 'background',
+			'control'           => 'upload',
 		) );
 
 		/* Nav Menus */
diff --git a/wp-includes/js/customize-controls.dev.js b/wp-includes/js/customize-controls.dev.js
index 5787499bb9..0b4baf1ccb 100644
--- a/wp-includes/js/customize-controls.dev.js
+++ b/wp-includes/js/customize-controls.dev.js
@@ -70,6 +70,26 @@
 		}
 	});
 
+	api.UploadControl = api.Control.extend({
+		initialize: function( id, value, options ) {
+			var control = this;
+
+			api.Control.prototype.initialize.call( this, id, value, options );
+
+			this.uploader = new wp.Uploader({
+				browser: this.container.find('.upload'),
+				success: function( attachment ) {
+					control.set( attachment.url );
+				}
+			});
+
+			this.container.on( 'click', '.remove', function( event ) {
+				control.set('');
+				event.preventDefault();
+			});
+		}
+	});
+
 	// Change objects contained within the main customize object to Settings.
 	api.defaultConstructor = api.Setting;
 
@@ -194,7 +214,8 @@
 	 * ===================================================================== */
 
 	api.controls = {
-		color: api.ColorControl
+		color:  api.ColorControl,
+		upload: api.UploadControl
 	};
 
 	$( function() {
@@ -229,6 +250,9 @@
 
 		// Background color uses postMessage by default
 		api('background_color').method = 'postMessage';
+
+		// api('background_image').method = 'postMessage';
+		api('background_image').uploader.param( 'post_data', { context: 'custom-background' });
 	});
 
 })( wp, jQuery );
\ No newline at end of file
diff --git a/wp-includes/js/plupload/wp-plupload.dev.js b/wp-includes/js/plupload/wp-plupload.dev.js
new file mode 100644
index 0000000000..8ad2738606
--- /dev/null
+++ b/wp-includes/js/plupload/wp-plupload.dev.js
@@ -0,0 +1,156 @@
+if ( typeof wp === 'undefined' )
+	var wp = {};
+
+(function( exports, $ ) {
+	/*
+	 * An object that helps create a WordPress uploader using plupload.
+	 *
+	 * @param options - object - The options passed to the new plupload instance.
+	 *    Requires the following parameters:
+	 *    - container - The id of uploader container.
+	 *    - browser   - The id of button to trigger the file select.
+	 *    - dropzone  - The id of file drop target.
+	 *    - plupload  - An object of parameters to pass to the plupload instance.
+	 *    - params    - An object of parameters to pass to $_POST when uploading the file.
+	 *                  Extends this.plupload.multipart_params under the hood.
+	 *
+	 * @param attributes - object - Attributes and methods for this specific instance.
+	 */
+	var Uploader = function( options ) {
+		var self = this,
+			elements = {
+				container: 'container',
+				browser:   'browse_button',
+				dropzone:  'drop_element'
+			},
+			key;
+
+		this.plupload = $.extend( { multipart_params: {} }, wpPluploadDefaults );
+		this.container = document.body; // Set default container.
+
+		// Extend the instance with options
+		//
+		// Use deep extend to allow options.plupload to override individual
+		// default plupload keys.
+		$.extend( true, this, options );
+
+		// Proxy all methods so this always refers to the current instance.
+		for ( key in this ) {
+			if ( $.isFunction( this[ key ] ) )
+				this[ key ] = $.proxy( this[ key ], this );
+		}
+
+		// Ensure all elements are jQuery elements and have id attributes
+		// Then set the proper plupload arguments to the ids.
+		for ( key in elements ) {
+			if ( ! this[ key ] )
+				continue;
+
+			this[ key ] = $( this[ key ] ).first();
+			if ( ! this[ key ].prop('id') )
+				this[ key ].prop( 'id', '__wp-uploader-id-' + Uploader.uuid++ );
+			this.plupload[ elements[ key ] ] = this[ key ].prop('id');
+		}
+
+		this.uploader = new plupload.Uploader( this.plupload );
+		delete this.plupload;
+
+		// Set default params and remove this.params alias.
+		this.param( this.params || {} );
+		delete this.params;
+
+		this.uploader.bind( 'Init', this.init );
+
+		this.uploader.init();
+
+		this.uploader.bind( 'UploadProgress', this.progress );
+
+		this.uploader.bind( 'FileUploaded', function( up, file, response ) {
+			response = JSON.parse( response.response );
+
+			if ( ! response || ! response.type || ! response.data )
+				return self.error( pluploadL10n.default_error );
+
+			if ( 'error' === response.type )
+				return self.error( response.data.message, response.data );
+
+			if ( 'success' === response.type )
+				return self.success( response.data );
+
+		});
+
+		this.uploader.bind( 'Error', function( up, error ) {
+			var message = pluploadL10n.default_error,
+				key;
+
+			// Check for plupload errors.
+			for ( key in Uploader.errorMap ) {
+				if ( error.code === plupload[ key ] ) {
+					message = Uploader.errorMap[ key ];
+					break;
+				}
+			}
+
+			self.error( message, error );
+			up.refresh();
+		});
+
+		this.uploader.bind( 'FilesAdded', function( up, files ) {
+			$.each( files, function() {
+				self.added( this );
+			});
+
+			up.refresh();
+			up.start();
+		});
+	};
+
+	Uploader.uuid = 0;
+
+	Uploader.errorMap = {
+		'FAILED':                 pluploadL10n.upload_failed,
+		'FILE_EXTENSION_ERROR':   pluploadL10n.invalid_filetype,
+		// 'FILE_SIZE_ERROR': '',
+		'IMAGE_FORMAT_ERROR':     pluploadL10n.not_an_image,
+		'IMAGE_MEMORY_ERROR':     pluploadL10n.image_memory_exceeded,
+		'IMAGE_DIMENSIONS_ERROR': pluploadL10n.image_dimensions_exceeded,
+		'GENERIC_ERROR':          pluploadL10n.upload_failed,
+		'IO_ERROR':               pluploadL10n.io_error,
+		'HTTP_ERROR':             pluploadL10n.http_error,
+		'SECURITY_ERROR':         pluploadL10n.security_error
+	};
+
+	$.extend( Uploader.prototype, {
+		/**
+		 * Acts as a shortcut to extending the uploader's multipart_params object.
+		 *
+		 * param( key )
+		 *    Returns the value of the key.
+		 *
+		 * param( key, value )
+		 *    Sets the value of a key.
+		 *
+		 * param( map )
+		 *    Sets values for a map of data.
+		 */
+		param: function( key, value ) {
+			if ( arguments.length === 1 && typeof key === 'string' )
+				return this.uploader.settings.multipart_params[ key ];
+
+			if ( arguments.length > 1 ) {
+				this.uploader.settings.multipart_params[ key ] = value;
+			} else {
+				$.extend( this.uploader.settings.multipart_params, key );
+			}
+		},
+
+		init:     function() {},
+		error:    function() {},
+		success:  function() {},
+		added:    function() {},
+		progress: function() {},
+		complete: function() {}
+	});
+
+	exports.Uploader = Uploader;
+})( wp, jQuery );
\ No newline at end of file
diff --git a/wp-includes/js/plupload/wp-plupload.js b/wp-includes/js/plupload/wp-plupload.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/media.php b/wp-includes/media.php
index e3b9008e34..e67563b87f 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -1441,3 +1441,46 @@ function wp_embed_handler_googlevideo( $matches, $attr, $url, $rawattr ) {
 
 	return apply_filters( 'embed_googlevideo', '<embed type="application/x-shockwave-flash" src="http://video.google.com/googleplayer.swf?docid=' . esc_attr($matches[2]) . '&amp;hl=en&amp;fs=true" style="width:' . esc_attr($width) . 'px;height:' . esc_attr($height) . 'px" allowFullScreen="true" allowScriptAccess="always" />', $matches, $attr, $url, $rawattr );
 }
+
+/**
+ * Prints default plupload arguments.
+ *
+ * @since 3.4.0
+ */
+function wp_plupload_default_settings() {
+	global $wp_scripts;
+
+	$max_upload_size = wp_max_upload_size();
+
+	$params = array(
+		'action' => 'upload-attachment',
+	);
+	$params = apply_filters( 'plupload_default_params', $params );
+
+	$params['_wpnonce'] = wp_create_nonce( 'media-form' );
+
+	$settings = array(
+		'runtimes'            => 'html5,silverlight,flash,html4',
+		'file_data_name'      => 'async-upload', // key passed to $_FILE.
+		'multiple_queues'     => true,
+		'max_file_size'       => $max_upload_size . 'b',
+		'url'                 => admin_url( 'admin-ajax.php' ),
+		'flash_swf_url'       => includes_url( 'js/plupload/plupload.flash.swf' ),
+		'silverlight_xap_url' => includes_url( 'js/plupload/plupload.silverlight.xap' ),
+		'filters'             => array( array( 'title' => __( 'Allowed Files' ), 'extensions' => '*') ),
+		'multipart'           => true,
+		'urlstream_upload'    => true,
+		'multipart_params'    => $params,
+	);
+
+	$settings = apply_filters( 'plupload_default_settings', $settings );
+
+	$script = 'var wpPluploadDefaults = ' . json_encode( $settings ) . ';';
+
+	$data = $wp_scripts->get_data( 'wp-plupload', 'data' );
+	if ( $data )
+		$script = "$data\n$script";
+
+	$wp_scripts->add_data( 'wp-plupload', 'data', $script );
+}
+add_action( 'admin_init', 'wp_plupload_default_settings' );
diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index 14f86bcb38..f1b9073345 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -228,6 +228,9 @@ function wp_default_scripts( &$scripts ) {
 	$scripts->add( 'plupload-handlers', "/wp-includes/js/plupload/handlers$suffix.js", array('plupload-all', 'jquery') );
 	$scripts->localize( 'plupload-handlers', 'pluploadL10n', $uploader_l10n );
 
+	$scripts->add( 'wp-plupload', "/wp-includes/js/plupload/wp-plupload$suffix.js", array('plupload-all', 'jquery', 'json2') );
+	$scripts->localize( 'wp-plupload', 'pluploadL10n', $uploader_l10n );
+
 	// keep 'swfupload' for back-compat.
 	$scripts->add( 'swfupload', '/wp-includes/js/swfupload/swfupload.js', array(), '2201-20110113');
 	$scripts->add( 'swfupload-swfobject', '/wp-includes/js/swfupload/plugins/swfupload.swfobject.js', array('swfupload', 'swfobject'), '2201a');