When my Dell laptop's HD went toes up, I made the big switch. Dell being Dell, I had no XP disk to reinstall from in the event of an emergency so being faced with the option of plunking down more cash for XP or (worse yet) dealing with Dell, I made the obvious choice and moved to Linux.
For quite some time, I've been spending more and more of my computer time running Linux from various live CD versions and the only thing on Windows that I actually cared about was Neverwinter Nights. The move to Linux was a no-brainer.
I have NWN up and running sort of - in fairness I haven't yet gotten sound to work and the performance is much worse with Hardy than it was with XP, but everything else is so much better (and cheaper!) now, I just don't see ever having a reason to move back to Windows.