Index: src/wp-admin/css/colors.css
===================================================================
--- src/wp-admin/css/colors.css	(revision 27103)
+++ src/wp-admin/css/colors.css	(working copy)
@@ -964,6 +964,44 @@
 	box-shadow: 0 1px 1px rgba(0,0,0,0.04);
 }
 
+.widget {
+	position: relative;
+	border-left: 0 solid transparent;
+	transition: border-left 0.2s ease-in-out;
+}
+.widget:before {
+	opacity: 0;
+	display: block;
+	content: "\f147";
+	transition: opacity 0.2s ease-in-out;
+	-webkit-font-smoothing: antialiased;
+	font: normal 32px/1 'dashicons';
+	position: absolute;
+		top: 2px;
+		left: -40px;
+	line-height: 43px;
+	color: #fff;
+}
+
+.widget.saved {
+	border-left: 48px solid #84d24c;
+}
+.widget.saved:before {
+	opacity: 1;
+}
+
+.spinner.error {
+	opacity: 1;
+	filter: alpha( opacity=100 );
+	background: url( '' );
+}
+
+.spinner.error:before {
+	font: normal 20px/1 'dashicons';
+	content: '\f335';
+	color: #a00;
+}
+
 #post-status-info {
 	border-top: none;
 }
Index: src/wp-admin/js/widgets.js
===================================================================
--- src/wp-admin/js/widgets.js	(revision 27103)
+++ src/wp-admin/js/widgets.js	(working copy)
@@ -332,10 +332,11 @@
 
 	save : function( widget, del, animate, order ) {
 		var sidebarId = widget.closest('div.widgets-sortables').attr('id'),
-			data = widget.find('form').serialize(), a;
+			data = widget.find('form').serialize(), a, spinner;
 
-		widget = $(widget);
-		$('.spinner', widget).show();
+		widget  = $(widget);
+		spinner = $('.spinner', widget);
+		spinner.show();
 
 		a = {
 			action: 'save-widget',
@@ -372,7 +373,7 @@
 					widget.remove();
 				}
 			} else {
-				$('.spinner').hide();
+				spinner.hide();
 				if ( r && r.length > 2 ) {
 					$( 'div.widget-content', widget ).html(r);
 					wpWidgets.appendTitle( widget );
@@ -381,6 +382,22 @@
 			if ( order ) {
 				wpWidgets.saveOrder();
 			}
+		})
+		.done( function() { // The widget save was successful, collapse the widget and alert the user
+			setTimeout( function() {
+				widget.find( '.widget-title' ).click();
+				widget.addClass( 'saved' );
+				setTimeout( function() {
+					widget.removeClass( 'saved' );
+				}, 2500 );
+			}, 100 );
+		})
+		.fail( function() { // The widget save failed, alert the user
+			if ( spinner ) {
+				spinner.show().addClass( 'error' ).delay( 1000 ).fadeOut( 'fast', function() {
+					spinner.removeClass( 'error' );
+				});
+			}
 		});
 	},