Does Bioshock install rootkit on your computer?

I've heard it does, but is this just false speculation? I'm talking about the Direct2Drive version by the way, if it makes a difference.

They never did. It was a blogger who misunderstood SecuROM for a rootkit. While a lot of us dislikes the SecuROM rootkit, we know that it is not a rootkit. And it never will be. The Sony Rootkit adventure showed publishers that that kind of behaviour is not accepted.