Steer the fuck clear from Vista. TOTAL PAIN IN THE ASS: It fucked up my ID, Illy and PS in about that order. And somehow it pissed all over my distiller too.
It is absolutely worthless if you are working on tightly integrated CS3 apps, CS3 is still buggy and when you add another buggy piece of software under it (Vista) it goes batshit insane. Stick to XP or OSX, as far as Ive used both it seems to me that OS related CS3 bugs are fewer on OSX then on XP too!