I'm finally taking the Vista jump and I'm not liking it so far.. but I really don't have much choice as I'm exceeding the 3GB memory limit on 32 bit XP often enough to make it annoying.
Just all the little things.. Install Java 5, Firefox doesn't launch web based Java apps.. Install Java 6, same thing. Except IE works fine.
Plus the way Vista does some things.. like ask ME if a program installed or uninstalled properly or not. Like I would know! You're the OS, not me, that's your job to keep track of the files and registry entries.