Sorry in advance to all the fan's of Laura Croft's ass in short shorts for what you're about to hear...
Straight from the Head of Studio over at Crystal Dynamics:
When Crystal Dynamics first set out to reboot the Tomb Raider franchise, there were two goals that we were extremely passionate about. The first was to create a modern Tomb Raider game that would surprise and excite gamers. The second was to make this the best game of our careers, something we would be really proud to be a part of. We truly believe that we have something very special on our hands and we can’t wait to share it with you.
Our priority now is to make sure we fully deliver the very highest quality game. In order to do this, we have decided to move the game’s release date by a few months, from Fall 2012 to the first quarter of 2013.
We’re doing things that are completely new to Tomb Raider in this game and the additional development time will allow us to put the finishing touches into the game and polish it to a level that you deserve. We believe this is the right choice and I guarantee it will be worth the wait. The game is looking amazing and we can't wait to show it to everyone at E3 in a few weeks. -Darrell Galahger, Head of Studio (Crystal Dynamics)
So it looks as though we won't be raiding any tombs until the first quarter of 2013 however, we will be getting some more info at E3 next month and they were nice enough to release another screenshot for us (above). Also, as I mentioned in regards to the Bioshock Infinite delay, this may seem sour at first but it's definitely a positive thing in the long run.