The mod they are using is the Forumhome in colums for 3.5.x by Xenon, as you can see it works just fine clean up to 3.7RC3 and will probably work with 3.7Gold when its released.

I'm also using it at my SEO Talk forums incase you wanted to see a variation of it

--------------------
David / vBulletin Setup Staff
Check out our Newsletter for the latest vB and SEO news.
Are you looking for vBulletin work to be done on your forums ?
Would you like to Help Support vBulletin Setup.
Check out my Webmaster Articles at the vBulletin Setup Blog! World of Warcraft Macros