Looks like Theo is looking for people to help with his latest project, a Group Communication System, like Spread, but with all the annoying bits fixed.
His list of goals looks encouraging, practically a laundry list of everything I hated about Tib/Rv back when I had to deal with it. Plus, Theo's one of those scary-smart people who's disturbingly good at most things, so if he's working on it I give it pretty good odds of kicking some serious ass.
Here's to hoping that his post pulls some contributors out of the woodwork. It would make total sense for people to work on this, it's the kind of tool that can be applied to practically any system, and the existing ones out there do have serious problems, either in functionality, reliability, licensing/cost, or most often all of the above.