It could be that one of the reasons that I find the new user interface in Windows Vista to be so distasteful is that I run Windows XP using the best theme ever: Royale Noir:
I find this so pleasant to work in that anything else looks like crap. It’s not exactly an official theme, but you should be able to find it with a little bit of work if you google “Royale Noir”. The best theory I’ve read about it so far is that it is an early version of the theme released with the Microsoft Zune media player software. In my opinion, Microsoft should have stopped at Royale Noir because the final Zune theme does not compare favorably.