I've been fooling with Vista on dual boot for awhile and have to say I see little advantage. My current gripe is HP still hasn't written the drivers so their All In One Photosmart printers can work on the LAN, via their ethernet connectors. There is stil, far as I know, only Trend Micro that makes a decent firewall for Vista (MS OneCare may not be as slick as it appears to be). I also had confusion using Aconis True Image which only a week ago issued a Vista compatible edition. By the way, if you've got XP on c:\ and Vista on d:\ these drive letters reverse when Vista boots and this causes some confusion with Acronis if you try to restore Vista. Solution seems to be to make a small boot c:\ and then install WinXP on d:\ and Vista on e:\. But, that requires reinstalling WinXP, and that doesn't make much sense if you're up and running.
Otherwise, far as I can see Vista isn't "magic". It essentially does what WinXP does: Run the programs you like and need.
Maybe when Vista SP2 comes out would be about time.