I was able to recreate the error by reverting back to the Nouveau driver. It still crashes with the 3.2.0-3-amd64 kernel, but it works with the 3.5-trunk-amd64 kernel. Although I'm only able to use the 'fall-back' mode of Gnome 3. This is probably due to the fact that Nouveau doesn't have hardware acceleration yet? I'm more than willing to test out any patches. Thanks!