Along with the new episodes, Eidos revealed that a Tomb Raider: Underworld demo will be downloadable from the Xbox Live Marketplace later in the month. nope
Set after the game's conclusion, the first chapter--Beneath the Ashes--add a new environment and enemies to the game. It will be available "in time for the holidays."
The second chapter--Lara's Shadow--brings "a new kind of playable character" to the mix, and will arrive in early 2009. No price point was mentioned for either episode.
In all, the two chapters are said to add six hours to the action-adventure game, which hits PC, PS2, PS3, Xbox 360, Wii, Nintendo DS and PSP on November 18.