Index: wp-admin/themes.php
===================================================================
--- wp-admin/themes.php	(revision 12736)
+++ wp-admin/themes.php	(working copy)
@@ -159,7 +159,7 @@
 
 <div class="wrap">
 <?php screen_icon(); ?>
-<h2><?php echo esc_html( $title ); if ( !is_multisite() || is_super_admin() ) { ?> <a href="theme-install.php" class="button add-new-h2"><?php echo esc_html_x('Add New', 'theme'); ?></a><?php } ?></h2>
+<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>
 
 <h3><?php _e('Current Theme'); ?></h3>
 <div id="current-theme">