Should I get Vista?

I'm getting a new computer and I'm not sure whether I should stick with XP or get Vista.  Besides, most of the problems are supposed to be fixed with SP1, right?  Also, how bad is that shit with DRM, or does that only apply to HD-DVD and Blu-ray?  Also, driver problems?

The computer I'm building has a quad-core.  Isn't Vista the only one that can properly utilize a quad-core with most programs?