Wow64node and two program files folders isn't a vista/win7 thing, it's a win64 thing - XP64 uses the same structure. This is a bit quirky, but not that big of a deal imho.
What I don't like is the "shadow stuff" vista (and thus win7) does - instead of making compatibility folders for programs that play dirty and try to write to their program folder, the OS should simply block access. Sure, it'd break a shitload of software, but perhaps that would be wake-up call to developers...
Anyway, Win7 is great. It really flies on my computer, definitely snappier than XP. I really love superfetch vs. XP's limited prefetcher (and yes, I do have the RAM to burn). With proper hardware acceleration the UI also feels smoother than XP, and there's no shearing/tearing when moving things around. And I really like the little UI touches, it's a great idea to merge the process bar and quicklaunch, and the ability to select individual tabs in IE is really nice, hope that firefox will be Win7-enabled soon.