On July 24 players can expect to see some new DLC for Left 4 Dead 2. This DLC is called “Cold Stream” and it will include a fan made campaign as well as ports of other maps from Left 4 Dead. The campaigns being ported over are: Death Toll, Dead Air, Blood Harvest, and Crash Course. Now you can play your Left 4 Dead favorites with Left 4 Dead 2′s characters and weapons.

The DLC will be available simultaneously for Xbox 360, Mac, and PC.

[SOURCE]