Theo has proposed a new distributed group communication project, called Anasazi.
I wish I had more spare time, just to work on it. Anasazi could be useful by all kinds of projects, not just things at $work.
There is a wiki too. Hopefully some companies can be convinced of the value of an open source GCS, and help with development. Open Source infrastructure projects, just like the Apache HTTP Server, are good for everyone involved.