Index: wp-admin/css/wp-admin.dev.css
===================================================================
--- wp-admin/css/wp-admin.dev.css	(revision 13465)
+++ wp-admin/css/wp-admin.dev.css	(working copy)
@@ -3666,4 +3666,34 @@
 
 div#custom-background-image p.submit {
 	display: inline;
+}
+
+/* Tab Interface */
+
+.menu-tabs {
+	border-width: 1px 1px 2px;
+	border-style: solid;
+	border-color: #ccc #ccc #f9f9f9;
+	color: #333333;
+	padding: 4px 20px 6px;
+	text-decoration: none;
+	background-color: #fafafa;
+	margin: 0 8px 0 0;
+	-moz-border-radius: 5px 5px 0 0;
+	-webkit-border-top-left-radius: 5px;
+	-webkit-border-top-right-radius: 5px;
+	-khtml-border-top-left-radius: 5px;
+	-khtml-border-top-right-radius: 5px;
+	border-top-left-radius: 5px;
+	border-top-right-radius: 5px;
+}
+
+.themes-php .wrap h2, .theme-install-php .wrap h2{
+	border-bottom: 1px solid #ccc;
+}
+
+.menu-tab-inactive{
+	border-width: 1px 1px 0;
+	background-color: #fafafa;
+	color: #c1c1c1;
 }
\ No newline at end of file
Index: wp-admin/theme-install.php
===================================================================
--- wp-admin/theme-install.php	(revision 13465)
+++ wp-admin/theme-install.php	(working copy)
@@ -58,7 +58,7 @@
 ?>
 <div class="wrap">
 <?php screen_icon(); ?>
-<h2><?php echo esc_html( $title ); ?></h2>
+<h2><a href="themes.php" class="menu-tabs menu-tab-inactive"><?php echo esc_html_x('Manage Themes', 'theme'); ?></a><a href="theme-install.php" class="menu-tabs"><?php echo esc_html( $title ); ?></a></h2>
 
 	<ul class="subsubsub">
 <?php
Index: wp-admin/themes.php
===================================================================
--- wp-admin/themes.php	(revision 13465)
+++ wp-admin/themes.php	(working copy)
@@ -134,7 +134,7 @@
 
 <div class="wrap">
 <?php screen_icon(); ?>
-<h2><?php echo esc_html( $title ); if ( current_user_can('install_themes') ) { ?> <a href="theme-install.php" class="button add-new-h2"><?php echo esc_html_x('Add New', 'theme'); ?></a><?php } ?></h2>
+<h2><a href="themes.php" class="menu-tabs"><?php echo esc_html( $title ); if ( current_user_can('install_themes') ) { ?></a> <a href="theme-install.php" class="menu-tabs menu-tab-inactive"><?php echo esc_html_x('Install Themes', 'theme'); ?></a><?php } ?></h2>
 
 <h3><?php _e('Current Theme'); ?></h3>
 <div id="current-theme">