So this seems like pretty good news for those of us wanting HL2 co-op. These guys seem to have a pretty good rep for the original sven co-op.
The one time I tried it about six months ago I couldn't get the game to tun for any length of time without iit freezing one of my pc's and ended up giving up on it, but maybe with Valve backing them and newer engine I'll have better luck this time around.
I'm glad to read this though. The thought of playing HL 2 with some friends sounds like a hell of a blast.