MJP:I installed RC1 on my old PC, and I liked it as well. Unfortunately ATI doesn't have a Win7 driver for the GPU in that maching (X1950 Pro), so I never even bothered to install XNA GS. I know people had it working in the beta, though.
Not sure where you were looking, but ATi has had a driver out for the x1950 for Win7 32 & 64 for at least several days now. I installed win 7 rc on the 5th... and the driver was already on ati's website. First thing I did was install Visual studio and xna, and the default driver that 7 installed for my x1950 pro even worked like a charm..
The taskbar is going to take some getting used to, and Im just going to dual boot Win 7 for a while.. since I put it on my dev machine.. lol.. that reminds me.. i need to remember to back up my projects folder..
Anyways, win 7 had and/or found drivers for every piece of hardware I have, even the hp printer and installed it all without issues. I did grab the latest ATI Catalyst 9.4 off ati's website for the x1950, since I need all the performance I can get out of my old rig.
http://game.amd.com/us-en/drivers_catalyst.aspx
That link is for the win 7 download for 32 & 64 bit versions.