Vista Tutorial - Broken WinFX install; suggestions?

When I installed VS2008 (beta 2) it trashed WinFX for 2.0 (or 3.0,
depending on your view); .NET 3.0 SP1 is "installed", but .NET 3.0
itself is dead, gone, no more. No dlls, no GAC, etc.

I can't reinstall WinFX from the install exe, since the installer
detects a newer version (presumably SP1); I can't uninstall SP1 since
it refuses (would break things... hah!); the change/repair option on
SP1 is a NOP.

So basically, I have no working WinFX, and no way to put it back. Does
anybody know a way out of this hole?

VS2008 reinstall has no effect. Looking around, this doesn't seem a
common problem, so I'm not saying it'll happen to you, but any help
would be appreciated...

I reported via connect, but it got closed with "cannot reproduce". Not
very helpful.

Marc