Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 22905)
+++ wp-includes/media.php	(working copy)
@@ -1507,7 +1507,7 @@
 	<script type="text/html" id="tmpl-media-modal">
 		<div class="media-modal">
 			<h3 class="media-modal-title">{{ data.title }}</h3>
-			<a class="media-modal-close" href="" title="<?php esc_attr_e('Close'); ?>">&times;</a>
+			<a class="media-modal-close media-modal-icon" href="#" title="<?php esc_attr_e('Close'); ?>"></a>
 		</div>
 		<div class="media-modal-backdrop">
 			<div></div>
@@ -1624,7 +1624,7 @@
 			<# } #>
 
 			<# if ( data.buttons.check ) { #>
-				<a class="check" href="#"><span>&#10003;</span><span class="dash">&ndash;</span></a>
+				<a class="check" href="#" title="<?php _e('Deselect'); ?>"><div class="media-modal-icon"></div></a>
 			<# } #>
 		</div>
 		<# if ( data.describe ) { #>
Index: wp-includes/css/media-views-rtl.css
===================================================================
--- wp-includes/css/media-views-rtl.css	(revision 22905)
+++ wp-includes/css/media-views-rtl.css	(working copy)
@@ -4,13 +4,11 @@
 .media-modal-title {
 	left: auto;
 	right: 0;
-	float: right;
 }
 
 .media-modal-close {
 	right: auto;
 	left: 0;
-	float: left;
 }
 
 /**
Index: wp-includes/css/media-views.css
===================================================================
--- wp-includes/css/media-views.css	(revision 22905)
+++ wp-includes/css/media-views.css	(working copy)
@@ -106,40 +106,29 @@
 .media-modal-title,
 .media-modal-close {
 	position: absolute;
-	top: -40px;
 	height: 40px;
-
-	line-height: 40px;
-	color: #fff;
-	font-weight: 200;
-	text-shadow: 0 0 16px rgba( 0, 0, 0, 0.6 );
 }
 
-a.media-modal-close {
-	color: #fff;
-}
-
 .media-modal-title {
+	top: -40px;
 	left: 0;
-	float: left;
 	padding: 0;
 	margin: 0;
+
+	line-height: 40px;
+	color: #fff;
 	font-size: 16px;
+	font-weight: 200;
+	text-shadow: 0 0 16px rgba( 0, 0, 0, 0.6 );
 }
 
 .media-modal-close {
+	top: -27px;
 	right: 0;
-	float: right;
-	text-decoration: none;
-	font-size: 1.8em;
+	width: 15px;
+	background-position: -80px 0;
 }
 
-.media-modal-close:hover,
-.media-modal-close:focus {
-	color: #fff;
-	text-shadow: 0 0 16px rgba( 255, 255, 255, 0.8 );
-}
-
 .media-modal-close:active {
 	outline: 0;
 }
@@ -154,6 +143,11 @@
 	background: #fff;
 }
 
+.media-modal-icon {
+	background-image: url(../images/uploader-icons.png);
+	background-repeat: no-repeat;
+}
+
 /**
  * Toolbar
  */
@@ -642,19 +636,13 @@
 	position: absolute;
 	top: -7px;
 	right: -7px;
-	line-height: 24px;
-	font-size: 16px;
-	text-align: center;
-	text-decoration: none;
 	outline: none;
 
-	color: #333;
 	border: 1px solid #fff;
 	border-radius: 3px;
-	text-shadow: 0 1px 0 #fff;
 	box-shadow: 0 0 0 1px rgba( 0, 0, 0, 0.4 );
 
-	background: #f1f1f1;
+	background-color: #f1f1f1;
 	background-image: -webkit-gradient(linear, left top, left bottom, from(#f1f1f1), to(#e1e1e1));
 	background-image: -webkit-linear-gradient(top, #f1f1f1, #e1e1e1);
 	background-image:    -moz-linear-gradient(top, #f1f1f1, #e1e1e1);
@@ -662,28 +650,25 @@
 	background-image:   linear-gradient(to bottom, #f1f1f1, #e1e1e1);
 }
 
-.attachment .check .dash {
-	font-weight: bold;
-	font-size: 18px;
-	line-height: 22px;
+.attachment .check div {
+	background-position: -1px 0;
+	height: 15px;
+	width: 15px;
+	margin: 5px;
 }
 
-.attachment .check .dash,
-.attachment .check:hover span {
-	display: none;
+.attachment .check:hover div {
+	background-position: -40px 0;
 }
 
-.attachment.selected .check,
-.attachment .check:hover .dash {
+.attachment.selected .check {
 	display: block;
 }
 
 .attachment.details .check {
-	color: #fff;
-	text-shadow: 0 1px 0 rgba( 0, 0, 0, 0.5 );
 	box-shadow: 0 0 0 1px #1e8cbe;
 
-	background: #1e8cbe;
+	background-color: #1e8cbe;
 	background-image: -webkit-gradient(linear, left top, left bottom, from(#1e8cbe), to(#0074a2));
 	background-image: -webkit-linear-gradient(top, #1e8cbe, #0074a2);
 	background-image:    -moz-linear-gradient(top, #1e8cbe, #0074a2);
@@ -691,6 +676,14 @@
 	background-image:   linear-gradient(to bottom, #1e8cbe, #0074a2);
 }
 
+.attachment.details .check div {
+	background-position: -21px 0;
+}
+
+.attachment.details .check:hover div {
+	background-position: -60px 0;
+}
+
 .media-frame .describe {
 	position: relative;
 	display: block;
@@ -703,6 +696,19 @@
 }
 
 /**
+ * HiDPI Displays
+ */
+@media print,
+  (-o-min-device-pixel-ratio: 5/4),
+  (-webkit-min-device-pixel-ratio: 1.25),
+  (min-resolution: 120dpi) {
+  	.media-modal-icon {
+  		background-image: url(../images/uploader-icons-2x.png);
+  		background-size: 95px 15px;
+  	}
+}
+
+/**
  * Attachments Browser
  */
 .media-frame .attachments-browser {