Here's a recent article Guru 3D did comparing Vista to Win7 in gaming performance. Basically, performance was very similar, which isnt hugely suprirising given that W7 6.1 is a derivative of the Vista 6.0 Kernel, and DX11 has full DX9/DX10 compatibility built in - but its good to see that W7 will be stable on release
Read the G3D Article
HERE
W7 did show some small gains in 1600p performance \o/
mtfbwya