Yep, there's a huge firestorm about the SecuRom copy protection on the Bioshock and Steam forums. It's such a hassle for legitimate customers, who have to call both 2kgames and SecuRom if they have a simple installation problem. I bought it anyway, but I don't like it.

I wish I had more time to play, but I spent about two hours trying to get a decent framerate (1.7Ghz Athlon, 1GB RAM, 6600GT), and trying to figure out why I kept crashing
every time I tried to switch levels. Downloading the recommended nVidia drivers seemed to solve this problem, which is caused by using a high-detail shader (or blooming, I forget which) graphics option when changing levels.
While trying to figure this out, I had to visit their forums, which is an inferno of complaints about game crashes, glitches, and technical bugs. I do think the game is buggy on the technical side, but if you can get it working you're golden. Gameplay looks bug-free so far.