http://360informer.com/2011/07/left-4-dead-2s-dlc-dead-air-arrives-on-or-before-july-22nd/
Earlier this month, Valve challenged the Left 4 Dead 2 community to unlock the Stream Crosser achievement by finishing the Cold Stream campaign on any difficulty level. The goal was to have 20,000 players complete the challenge with the reward being a new DLC for the game.
Just 24 hours after the challenge was distributed, the achievement was achieved 60,774 times. And Valve understands that they will need to cough up that DLC soon – soon being on or before July 22nd.
Valve explained that the reason for the uncertainty in regards to the release date is because they want to ship out the DLC as soon as it’s finished, so with that being said, the DLC is still in the works.
