At this point, the game is expected sometime between mid 2013 and 2014.
Take-Two delivered a financial report yesterday and revealed a few interesting things. In between the sales figures and other tidbits, the company also announced a significant delay for 'XCOM.' Instead of coming out before March of 2013, it's now expected anywhere between April of 2013 and March of 2014. That's a pretty hefty release window.
Fans of the old-school turn based strategy game 'XCOM' haven't exactly been thrilled to see the title turned into an FPS. To those folks, this is almost certainly welcome. To everyone who never played XCOM, well, it's probably not even a blip on the radar.