We had one on AIM. Someone just made a room, posted the name, and people would set a time to meet in there. Everyone had to have an AIM account to get in.
I wouldn't mind seeing it come back. Nils probably ends up policing it though. And maintaining it for security. That sounded like a pain.
I think it emphasizes the people more. The level of conversation seemed a little shallower than the forum here.