XP has had a 8 year run, longer then any version of windows to date. Its only natural that they want to sell more vista. The more they sell, the more the lazy ass driver developers get there act together. Vista is not the problem, for the most part its the drivers(Many do not quite work right(creative lacks features and stability, Nvidia had several issues), but they had the new driver model long time before vista hit the selves.)
XP had just as many problems when it came out(maybe even more), but after 8 years its been almost perfected. Vista is moving along faster then XP did(most things are taken care of faster then similar issues on XP).