Yes and No. While it is supposedly more secure (for now), the plain fact is that Vista relies on DRM, with polling every second, which will eat cpu cycles and memory. Tilt bits are not to be messed with, it'll either restart the video subsystem or cause it to reboot. But think about it - Vista can degrade your video at whim. Vista is made to cripple a system if it so chooses.
No thanks. I'll stick with XP, OSX and Linux. I have no intention of running my computer as a media centre. Why the hell would I?, the fans are too loud, the wattage too high. I figure it'll only be useful as HTPC, a nice quiet box where there are no fans in the power supply, no fans on the cpu, the northbrdge, the southbridge, the video card, the disc drives. It has to be 100% passive cooling. No, I don't know what water cooling sounds like when the pump kicks in. I'll wait until a box comes out which will cost $100 and do the same thing. I have absolutely no interest in reading my email on the Plasma TV, thank you very much, nor in listening to music which has been downloaded and is so highly compressed that it is painful to listen to. Download movies? No fricking way, I pay $15 a month to Hollywood video to be able to take any 3 second run movies out at any one time, with 5 day return period. So, let's see, no internet, no video, no music, no telephone, no on-line gaming. Nope, I don't need Vista.