Index: wp-includes/template-loader.php
===================================================================
--- wp-includes/template-loader.php	(revision 18922)
+++ wp-includes/template-loader.php	(working copy)
@@ -6,6 +6,11 @@
 if ( defined('WP_USE_THEMES') && WP_USE_THEMES )
 	do_action('template_redirect');
 
+// Halt template load for HEAD requests, a performance bump
+if ( !defined('PROCEED_AFTER_HEAD') || PROCEED_AFTER_HEAD !== true )
+        if ( $_SERVER['REQUEST_METHOD'] == 'HEAD' && apply_filters( 'exit_on_http_head', true ) )
+                exit();
+
 // Process feeds and trackbacks even if not using themes.
 if ( is_robots() ) :
 	do_action('do_robots');