In a letter to the press this morning, developer Bethesda basically outlined what's been going on with the project. It looks as though Prey 2 wasn't shaping up the way it was envisioned and the holdup (and subsequent delay) is to give development a little while longer. So basically, don't expect to see the game this year.
Below is the letter from BethSoft:
So there you have it- no alien bounty huntin' till 2013 at the earliest. Hopefully we'll hear more at E3 since P2 was on more than a few 'games to watch' lists and was shaping up pretty nicely.