I, for one, have no plans to go back to Vista (or XP, gawd forbid...)
Given the choice between Vista and XP, I'd pick XP any day of the week.
Win7 is showing promise though. I'll likely use that unless they somehow manage to completely mess it up between now and release. Vista marks the only MS OS I've completely skipped since 3.0 or so. Well, not counting Me, but I don't think even Microsoft counts that one.