To be fair to Vista
I remember when XP first came out there were lots of broken applications, dodgy driver support and at the time it was a real resource hog compared to the extremely nippy Win98 and didn't really offer much over Win2K beyond booting more quickly.
So I do wonder if maybe in 3 years time or so we'll all be quite happy with Vista and have forgotten all the problems at the moment. I think the answer could be yes, were it not for the DRM infections which cause file copies/deletions to take forever etc. I do wonder if that is really a step too far and it will push more and more people to XP/OSX/Linux.
It's a bit like the PS3 really, MS have been the market leader for so long, it's hard to tell if the momentum of being the market leader means Vista will succeed despite being crap or if this really is the turning point, especially with so many apps now becoming web based making the OS less and less pivotal.