I run it on both environments (XP Pro and Vista Ultimate). There are only two
things I had to get used to in Vista, one of them is supposed to get fixed in
the Vista SP1, we'll see.

1. In order to use VS2008 correctly in Vista, you need to right click the
icon and Run as Administrator. If you don't and you are attaching to a site
on the localhost, you won't be able to save files (at least I couldn't).
Running as an admin allows you to do this. I understand this functionality
will be corrected in Vista SP1.

2. If you are using the IIS in Vista in your development environment, you
will need to manually set it up to register running ASP.NET. IIS in Vista and
in Server 2008 out of the box serves pretty much HTML and that's it. This is
actually a good thing for security. I forget the exact article and procedure,
I did it a while ago, but I'm sure someone here can push you in the right
direction.

Other than those two requirements, I've had no problem running VS2008 or
VS2005 for that matter on Vista. I guess it comes down to more of a question
of which OS platform you prefer than anything else.

HTH.