I'm currently running 3.7 Beta 2 of WordPress. I downloaded and installed this theme, switched it on and it works like a charm.
Three columns AND it's responsive.
The two level horizontal approach to drop down menus is a welcome change.
Most importantly, it's accessible* which is a rarity in the WordPress Theme directory.
*I prefer the word inclusive to accessible but until the name change becomes more widespread I'll stick with accessible so that people know what I'm talking about.