It is very stable and its even faster than xp, and since the launch is very soon lots of drivers are out for windows 7 right now so at launch, or infact right now u also shouldnt be afraid of compatibility
I am running Windows 7 for x86 (That's 32 bit for you non-savy people), and I can honestly say I love it. I've been an XP User for a long time, ever since it came out. I believe that first time I used it was when the Xp Upgrade disc came out, I was running 98 SE then.
I made the switch because my computer wasn't playing nice with other computers, never figured out why but I couldn't LAN. I was going to format anyway, so I decided to try out Win7, since I got it for FREE from my school
Everything I used to use, minus my firewall software, which is fine; it all still works. I haven't run into any problems with it yet. Go ahead, upgrade. Win7 is great. Plus, Dx10 can't be bad either I haven't had problems finding any drivers either.
Don't go vista if you can wait for windows 7 i used to use vista before i upgraded to vista and i have seen a noticeable change in performance on my rig, and that is just with the RC so I have high hopes for the full edition.