I'm not one to post a bunch of rumors. I hate when they are good ones and then they end up being false or a joke started to get views. I really hate it. But this is a rumor that I think most of the fans of 2K Games would go ballistic over if it was made to be a joke or for publicity. It's also one that I am sure that any fan of BioShock would love to be true.
If you could not deduce by now, the rumor is BioShock: The MMO. Yea, you just read that, and you know what, it makes sense. In fact, I could see it being a rather decent MMO as well. Granted there would be only two major factions and "races," but if you think about it, it would work. That was pretty much the concept behind everything, a large society of people who "level up" their powers and skills. All the while going crazy and trying to kill each other for survival. It'd be just like the new multiplayer in concept.
Granted, that is just me spit balling, but it could be something pretty cool if done right or at all. Kind of like a super charged and truly level based version of BioShock 2 Multiplayer. Here's hoping. Expect to be updated as soon as we get more information.