As someone who'd rather not be on Windows...
...but likes PC games too much to dump it, I'm not really having any issues with Vista. I've never seen the "long goodbye" file copy issues. All the programs I use work just fine under Vista. I can't imagine using it in an office enviroment, too much fluff. For a home user mainly interested in games it's serviceable.
My wife's new Dell, however, came with Vista pre-installed, and it's not behaving nearly as well as mine. The whole system seems sluggish and came with several programs that have automatic updaters that need to run as admin EVERYTIME THEY CHECK FOR AN UPDATE OH GOD. That's pretty annoying. Good going with that, Dell. I'll be sure to make wiping the HD the first order of business next time (if there is a next time) I buy your wares.
If DX10 was available for XP, I wouldn't have "upgraded". I would have had no reason to.