Valve recently announced another expansion for its cooperative zombie-shooter Left 4 Dead 2. The new DLC will bring in the final three remaining levels from the original Left 4 Dead campaign and “Cold Stream”, a user-developed level by Matthew Lourdelet (who also created the user map “2 evil eyes”). The DLC is set to launch after Portal 2‘s April 20th release date, and the folks at Valve have already set up a feedback forum thread for the new content.