Oh, side note. There is going to be a zombie/pr night coming up. They are altering the maps to include heavy fog, limit kits, decrease spawn times and have 16 survivors try to make it through a city filled with 48 zombies. Should be awesome.
Edit: Here is a video from one of the other pr/zombie nights they have had. Everybody is in the same mumble channel, so it's like TS except that your voice appears to come from your in-game character. All the zombies moan and cry for brains while the survivors try to organize a defense against a zombie hoard! I'm kind of excited about it.