I'm currently testing a build of Windows Vista on my scratch/development machine. First impressions: not particularly impressed. I think I'll be sticking with Windows XP for the forseeable future.
The main problems are that it's horribly slow and seriously annoying with all the breaks in workflow that the default settings impose on me, even in an admin account. I think that I'll be switching off a lot of the "safety features" and other fluff which are turned on by default to see if that makes any kind of difference.
The other big problems: I can't install the Beta 2 edition of Office that I have on Vista because I have "non US" settings. Well pardon me for having a UK setup! Oddly enough, I also can't install Visual Studio 2005 for similar reasons. WTF!!! And this is supposed to be close to shippable code (Beta 2 build). God knows what kind of chance someone with non Roman-based languages, such as Korean or Japanese stands of getting anything out of Vista. How could something so fundamental as language options be broken? Isn't this code supposed to be based on the XP code-base?
Maybe I'll try re-installing it using non UK settings and see how things go with that.
More opinions later, once I've done some more testing...