I wonder how they will monetize this? A white-label chat platform for websites that want a chat facility would be one option (StackOverflow rolled out chat recently, but this would have been a good candidate for them). Branded in-house chat for corporates would be another, especially those with distributed project teams that want to communicate around a project. I like the fact that the chat sessions are persistent and revolve around a topic - this makes them very useful in a project environment.