actually, she said the disc-version only uses SecuROM for disk-checking purposes. however, she didn't literally say the Steam version doesn't include it, and so far the store page hasn't been changed.
a direct quote from her:
As many of you are aware, yesterday Steam's pre-purchase program began and the specs for BioShock 2 were posted along with that announcement.
These specs were taken from the retail packaging of BioShock 2. And since bullet points on the back of the box don't always explain the full story, here is a little more detail about what that means.
BioShock 2 is using a standard Games for Windows Live activation system, much like other games you have played in the past. That doesn't mean you always have to be online to play or save the game - you can create an offline profile for the Single Player portion of the game (you just won't earn achievements and you can't play Multiplayer, of course.)
We are using SecuROM only as a disc check method for the retail copy of BioShock 2. That is it's only use.
yes, it's a bit of a conspiracy theory to say that the Steam version DOES include SecuROM, but so far we have only a statement saying otherwise. I do believe the Steam copy doesn't include it, but I guess we should wait for a real confirmation.
the words above were backed by NUCLEAR WEAPONS!