Bioshock's officially activated on Steam. If you pre-loaded the game, you can now play it, no wait required. If you haven't checked it out yet, definitely hit up the demo. Also don't forget to use the beta nVidia drivers or the AMD/ATi hotfix.

I played through the demo on my rig using the latest official nVidia drivers (162.18). I used a combination of high settings at 1600X900 & got 30-60fps. I'm doubting that the beta drivers will improve my performance all that much, but I don't really intend to buy the game anytime soon; even though the demo was pretty kick-ass.