Microsoft today confirmed that the ‘Survival Pack’ for Left 4 Dead will be releasing on April 21st on the Xbox 360.
The DLC will be free of charge, and introduces a new multiplayer game mode entitled, Survival, plus two complete campaigns for Versus Mode (Death Toll, Dead Air).
Although the release date has not been confirmed for the PC, it can be expected to arrive near if not on the date, since Valve have said they wished to release the content simultaneously.