Well, since the MP community looks like its going to be close to nil in Crysis like it was in Farcry, I can just wait until they get Vista's sp1 out. Crysis will likely be down to 20 or 30 bucks.
I tried Vista on my computer (6600 d2c/2GB 800mhz DDR2/8800 640MB GTS) and I really just didn't care for it. All the damn permission crap, the fact that a majority of the apps I mainly use didn't work yet in Vista just made want to hold off.
I only see this move hurting Crysis's sales, or at least first release sales. I am sure a lot of people like myself will buy the game when its cheaper and Vista isn't as annoying.