Take-Two has confirmed that the recently-founded 2K Marin is currently developing Bioshock 2. The sequel to 2007's hit title Bioshock, developed by 2K Boston and 2K Australia, will be arriving in fourth quarter 2009 and it is rumoured to be a prequel to the original. The first Bioshock has sold 2 million units to date. Why the sequel has been taken away from it's original developers is not clear but it is thought that 2K Boston and 2K Australia are working on an entirely new project. Take Two have said as much but also intimated that 2K Boston and 2K Australia will also work on the BioShock sequel but their focus is elsewhere at the moment.