I think the look of Vista is pretty decent but I'll just download a Vista-ish skin for XP in the near future and I'll get the same transparent menus and windows... I quite like that wallpaper too by the way.
The whole ALT+TAB thing seems to be one of the biggest marketing points for Microsoft while it's pretty ordinary and looks rather tacky in my opinion. I think Microsoft have clearly drawn inspiration from Apple with their meters and gauges, style and their ways of navigating.
From what I've understood, Office Vista is supposedly much easier to use now, but it's probably a matter of getting used to for the experienced Office XP users...