Windows 7 is pre-beta and not fully developed. It wont be out for another year.
I love Vista. But i am just saying. If you go ahead with it and the onboard doesnt support the Aero interface you should know thie before.
Vista does DX10 but it just needs a DX9 video card for Aero support. There are lists all over the net that can tell you if the gfx can do Aero or not.