Looks like Eidos is pulling a GTA4 for Tomb Raider: Underworld. According to a press release, they will be offering two sets of exclusive downloadable content for the Xbox 360 version of the game.

The first DLC chapter, titled "Beneath the Ashes," will be arriving this Christmas. and will take place after the story of Underworld. The DLC will feature a "new environment to explore, additional secrets to unlock and different enemies to fight."

The second chapter will arrive early 2009, and will be titled "Lara's Shadow." I'm curious about this one because the press release only describes it to introduce a "new kind of playable character and create a unique Tomb Raider experience." I doubt they can introduce a character that can take the spotlight off Lady Croft though.

Incidentally, a demo of the game will be out this month. Also an exclusive for the Xbox 360? Most likely. Tomb Raider: Underworld will be released for the PlayStation 3, Xbox 360, and the Wii on November 18 for North America, and November 21 for Europe.