Unlock Left 4 Dead's Next Map Early By Play-Testing "Dead Air"

The importation of original Left 4 Dead maps into Left 4 Dead 2 rolls on, with the latest update to "Dead Air" delivering a new version of the Terminal map. Valve says the update brings matters "pretty close to being complete" but "at this stage what we really need is more testing." It's found a way to get you to do…