BioShock creator Ken Levine has said that he makes no claim on Bioshock 2 whatsoever. It's a 2K Marin project, and the dev team have to put their stamp on it.
"If I'm not working on a project -- I'm not working on BioShock 2," said Ken to Gama. "I make no claim to anything on BioShock 2, and I think it's important that that's their product, and their culture. Because you can't just clone a studio.
"I think that their hunger to do something new will be very important to their success there.
"And it can't just be a clone of a 2K Boston or Irrational Games; 2K Marin has to be its own thing. And a very separate thing," he explains.
"They're working on BioShock, but it's got to be their project. They've got to put their stamp on it."
Bit more through the link.
Bioshock 2 was recently delayed into next year.