Go out and get it while it's hot!
Available in both English and Japanese. 372 megs for the version that addresses all non-express versions of Visual Studio. 17-23 megs for the Express versions. Lots of bugfixes and upgrades for better perf. Muchly appreciated. By the way, this is 100% updates to the IDE, no changes whatsoever to the .NET Framework 2.0.
More info available from Soma Somasegar's blog post:
Of key interest to me was Soma's comment that the folks in MS Developer Division had to make a decision between making SP1 fully compatible with Vista RTM or releasing it early so everyone could benefit from it now. And the feedback they got was to go ahead and ship it earlier, with another follow-up service pack coming along when Vista ships. Good move in my opinion.