Interestingly enough - I HAVE TO use alt+tab.
For whatever reason, whether I let the launch movie play through or ESC past it (yes, yes the game still needs to finish loading.. .whatever) --- I get a black screen. Never resolves on its own. I alt+tab back and forth a few times and it pops -- but I have to click the 'OK' via the Vista alt+tab representations (i.e., the windows of the different 'tabs'); if I just move to the interface, black screen again.
core2 at 2.67 ghz, 6 gig RAM, 1 gig GeForce, so I'm pretty sure it's not it an equipment issue.
I think I'm just going to blame it on Steam because whether it's actually the cause or not, I've already grown to hate Steam enough to blame it for things that aren't its fault... It just feels right.