Canonical, the guys behind Ubuntu Linux, seem to be creating a “next-generation distributed version control system” called Bazaar-NG. It’s written in Python and is primarily tested on Ubuntu. I haven’t played with it but it seems it is already self-hosting, that demonstrates a bit of its capabilities. They have excellent documentation already. Although, I am wondering how they are going to handle the ‘distributed’ part.
Update : The lead guy on Bazaar-NG is also the person who wrote DistCC. So, I guess he knows what he’s doing ;)