diff --git a/modules/angular2/src/forms/model.js b/modules/angular2/src/forms/model.js
index ae63afd135..62698ef371 100644
--- a/modules/angular2/src/forms/model.js
+++ b/modules/angular2/src/forms/model.js
@@ -1,4 +1,5 @@
 import {isPresent} from 'angular2/src/facade/lang';
+import {Observable, ObservableWrapper} from 'angular2/src/facade/async';
 import {StringMap, StringMapWrapper} from 'angular2/src/facade/collection';
 import {Validators} from './validators';
 
@@ -21,39 +22,32 @@ export class AbstractControl {
   _value:any;
   _status:string;
   _errors;
-  _updateNeeded:boolean;
   _pristine:boolean;
   _parent:ControlGroup;
   validator:Function;
 
   constructor(validator:Function) {
     this.validator = validator;
-    this._updateNeeded = true;
     this._pristine = true;
   }
 
   get value() {
-    this._updateIfNeeded();
     return this._value;
   }
 
   get status() {
-    this._updateIfNeeded();
     return this._status;
   }
 
   get valid() {
-    this._updateIfNeeded();
     return this._status === VALID;
   }
 
   get errors() {
-    this._updateIfNeeded();
     return this._errors;
   }
 
   get pristine() {
-    this._updateIfNeeded();
     return this._pristine;
   }
 
@@ -65,35 +59,38 @@ export class AbstractControl {
     this._parent = parent;
   }
 
-  _updateIfNeeded() {
-  }
-
   _updateParent() {
     if (isPresent(this._parent)){
-      this._parent._controlChanged();
+      this._parent._updateValue();
     }
   }
 }
 
 export class Control extends AbstractControl {
+  valueChanges:Observable;
+  _valueChangesController;
+
   constructor(value:any, validator:Function = Validators.nullValidator) {
     super(validator);
-    this._value = value;
+    this._setValueErrorsStatus(value);
+
+    this._valueChangesController = ObservableWrapper.createController();
+    this.valueChanges = ObservableWrapper.createObservable(this._valueChangesController);
   }
 
   updateValue(value:any) {
-    this._value = value;
-    this._updateNeeded = true;
+    this._setValueErrorsStatus(value);
     this._pristine = false;
+
+    ObservableWrapper.callNext(this._valueChangesController, this._value);
+
     this._updateParent();
   }
 
-  _updateIfNeeded() {
-    if (this._updateNeeded) {
-      this._updateNeeded = false;
-      this._errors = this.validator(this);
-      this._status = isPresent(this._errors) ? INVALID : VALID;
-    }
+  _setValueErrorsStatus(value)  {
+    this._value = value;
+    this._errors = this.validator(this);
+    this._status = isPresent(this._errors) ? INVALID : VALID;
   }
 }
 
@@ -101,21 +98,29 @@ export class ControlGroup extends AbstractControl {
   controls;
   optionals;
 
+  valueChanges:Observable;
+  _valueChangesController;
+
   constructor(controls, optionals = null, validator:Function = Validators.group) {
     super(validator);
     this.controls = controls;
     this.optionals = isPresent(optionals) ? optionals : {};
+
+    this._valueChangesController = ObservableWrapper.createController();
+    this.valueChanges = ObservableWrapper.createObservable(this._valueChangesController);
+
     this._setParentForControls();
+    this._setValueErrorsStatus();
   }
 
   include(controlName:string) {
-    this._updateNeeded = true;
     StringMapWrapper.set(this.optionals, controlName, true);
+    this._updateValue();
   }
 
   exclude(controlName:string) {
-    this._updateNeeded = true;
     StringMapWrapper.set(this.optionals, controlName, false);
+    this._updateValue();
   }
 
   contains(controlName:string) {
@@ -129,14 +134,19 @@ export class ControlGroup extends AbstractControl {
     });
   }
 
-  _updateIfNeeded() {
-    if (this._updateNeeded) {
-      this._updateNeeded = false;
-      this._value = this._reduceValue();
-      this._pristine = this._reducePristine();
-      this._errors = this.validator(this);
-      this._status = isPresent(this._errors) ? INVALID : VALID;
-    }
+  _updateValue() {
+    this._setValueErrorsStatus();
+    this._pristine = false;
+
+    ObservableWrapper.callNext(this._valueChangesController, this._value);
+
+    this._updateParent();
+  }
+
+  _setValueErrorsStatus()  {
+    this._value = this._reduceValue();
+    this._errors = this.validator(this);
+    this._status = isPresent(this._errors) ? INVALID : VALID;
   }
 
   _reduceValue() {
@@ -146,11 +156,6 @@ export class ControlGroup extends AbstractControl {
     });
   }
 
-  _reducePristine() {
-    return this._reduceChildren(true,
-      (acc, control, name) => acc && control.pristine);
-  }
-
   _reduceChildren(initValue, fn:Function) {
     var res = initValue;
     StringMapWrapper.forEach(this.controls, (control, name) => {
@@ -161,11 +166,6 @@ export class ControlGroup extends AbstractControl {
     return res;
   }
 
-  _controlChanged() {
-    this._updateNeeded = true;
-    this._updateParent();
-  }
-
   _included(controlName:string):boolean {
     var isOptional = StringMapWrapper.contains(this.optionals, controlName);
     return !isOptional || StringMapWrapper.get(this.optionals, controlName);
diff --git a/modules/angular2/src/forms/validators.js b/modules/angular2/src/forms/validators.js
index fd5e3ccbe0..dbce2a560c 100644
--- a/modules/angular2/src/forms/validators.js
+++ b/modules/angular2/src/forms/validators.js
@@ -8,7 +8,7 @@ export class Validators {
     return isBlank(c.value) || c.value == "" ? {"required": true} : null;
   }
 
-  static nullValidator(c:modelModule.Control) {
+  static nullValidator(c:any) {
     return null;
   }
 
diff --git a/modules/angular2/test/forms/model_spec.js b/modules/angular2/test/forms/model_spec.js
index 69a732c3b8..5252e45b0d 100644
--- a/modules/angular2/test/forms/model_spec.js
+++ b/modules/angular2/test/forms/model_spec.js
@@ -1,5 +1,8 @@
-import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach, el} from 'angular2/test_lib';
-import {ControlGroup, Control, OptionalControl, Validators} from 'angular2/forms';
+import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach, el,
+  AsyncTestCompleter, inject} from 'angular2/test_lib';
+import {ControlGroup, Control, OptionalControl, Validators} from 'angular2/forms';;
+import {ObservableWrapper} from 'angular2/src/facade/async';
+import {ListWrapper} from 'angular2/src/facade/collection';
 
 export function main() {
   describe("Form Model", () => {
@@ -188,6 +191,115 @@ export function main() {
           expect(group.valid).toEqual(false);
         });
       });
+
+      describe("valueChanges", () => {
+        describe("Control", () => {
+          var c;
+
+          beforeEach(() => {
+            c = new Control("old");
+          });
+
+          it("should fire an event after the value has been updated",  inject([AsyncTestCompleter], (async) => {
+            ObservableWrapper.subscribe(c.valueChanges, (value) => {
+              expect(c.value).toEqual('new');
+              expect(value).toEqual('new');
+              async.done();
+            });
+            c.updateValue("new");
+          }));
+
+          it("should return a cold observable",  inject([AsyncTestCompleter], (async) => {
+            c.updateValue("will be ignored");
+            ObservableWrapper.subscribe(c.valueChanges, (value) => {
+              expect(value).toEqual('new');
+              async.done();
+            });
+            c.updateValue("new");
+          }));
+        });
+
+        describe("ControlGroup", () => {
+          var g, c1, c2;
+
+          beforeEach(() => {
+            c1 = new Control("old1");
+            c2 = new Control("old2")
+            g = new ControlGroup({
+              "one" : c1, "two" : c2
+            }, {
+              "two" : true
+            });
+          });
+
+          it("should fire an event after the value has been updated", inject([AsyncTestCompleter], (async) => {
+            ObservableWrapper.subscribe(g.valueChanges, (value) => {
+              expect(g.value).toEqual({'one' : 'new1', 'two' : 'old2'});
+              expect(value).toEqual({'one' : 'new1', 'two' : 'old2'});
+              async.done();
+            });
+            c1.updateValue("new1");
+          }));
+
+          it("should fire an event after the control's observable fired an event", inject([AsyncTestCompleter], (async) => {
+            var controlCallbackIsCalled = false;
+
+            ObservableWrapper.subscribe(c1.valueChanges, (value) => {
+              controlCallbackIsCalled = true;
+            });
+
+            ObservableWrapper.subscribe(g.valueChanges, (value) => {
+              expect(controlCallbackIsCalled).toBe(true);
+              async.done();
+            });
+
+            c1.updateValue("new1");
+          }));
+
+          it("should fire an event when a control is excluded", inject([AsyncTestCompleter], (async) => {
+            ObservableWrapper.subscribe(g.valueChanges, (value) => {
+              expect(value).toEqual({'one' : 'old1'});
+              async.done();
+            });
+
+            g.exclude("two");
+          }));
+
+          it("should fire an event when a control is included", inject([AsyncTestCompleter], (async) => {
+            g.exclude("two");
+
+            ObservableWrapper.subscribe(g.valueChanges, (value) => {
+              expect(value).toEqual({'one' : 'old1', 'two' : 'old2'});
+              async.done();
+            });
+
+            g.include("two");
+          }));
+
+          it("should fire an event every time a control is updated", inject([AsyncTestCompleter], (async) => {
+            var loggedValues = [];
+
+            ObservableWrapper.subscribe(g.valueChanges, (value) => {
+              ListWrapper.push(loggedValues, value);
+
+              if (loggedValues.length == 2) {
+                expect(loggedValues).toEqual([
+                  {"one" : "new1", "two" : "old2"},
+                  {"one" : "new1", "two" : "new2"}
+                ])
+                async.done();
+              }
+            });
+
+            c1.updateValue("new1");
+            c2.updateValue("new2");
+          }));
+
+          xit("should not fire an event when an excluded control is updated", inject([AsyncTestCompleter], (async) => {
+            // hard to test without hacking zones
+          }));
+        });
+      });
     });
   });
-}
+}
\ No newline at end of file