Left 4 Dead DLC

For those of you who have been anticipating it (not for very long, considering it's Valve), the Left 4 Dead DLC has been dated.
Microsoft has confirmed that the ‘Survival Pack’ for Left 4 Dead will be releasing on April 21st on the Xbox 360, free of charge (w00t). This pack introduces a new 'Survival' multiplayer game mode and support for Dead Air and Death Toll in Versus. While Valve has said that they wished to release the content simultaneously, no word yet on the PC release date.

Get your shotguns ready.

For more info on Survival Mode, see the IGN preview.

[Source]