The next major release of WordPress is just around the corner — April 16th is the scheduled release date for WordPress 3.9. It will also be the very first version of WordPress with this little patch of mine running behind the scenes which enables plugins to improve the performance of rendering menus. In theory, it should save up to six database queries on each page load!
I have updated the Widget Output Cache plugin to include this new filter and add support for caching the menu output. Membership and e-commerce websites (and others with mostly logged-in users) should see the biggest performance improvement and decreased page load times. Be sure to check it out.