The Eidos Forums have word that Crystal Dynamics' reboot of Tomb Raider is delayed until the first quarter of next year, after being planned for release this year. Here's a statement from Darrell Gallagher, the Crystal Dynamics studio head:

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.