Take-Two's earning statement confirms BioShock 2 is coming in fiscal year 2009. That would likely put its release sometime next holiday season. 

The report's formatting initially had PS3, Xbox 360 and PC next to BioShock 2 but it has since been revised with "TBA." With BioShock coming to PS3 shortly the odds of BioShock 2 being developed for both consoles are worth betting on. Whether it will appear on Xbox 360 first as a timed exclusive remains to be seen. Full Article