It looks interesting, I wonder if these type of projects will eventually replace IRC. I could definitely see popular open source projects using this over IRC, especially if they have features like snippet embedding.
I've been using convore and thinking about it in terms of asynchronous IRC with sub-channels. (i.e. each group is a channel, and each topic is a sub-channel composed of the same channel members, with a different topic.)
A topic is more like a forum topic/thread.