This is a very valid point. It is not clear at all that a single repo for the world is desirable in the long run, despite some of the individual advantages tha

This is a very valid point. It is not clear at all that a single repo for the world is desirable in the long run, despite some of the individual advantages that sort of setup has. It is part of the reason that I don't think we will see the "next generation" of VCS anytime soon. (Which in turn makes me think that "holding out" for those systems, hoping they will rescue you from your scaling problem, is a bad decision. It is best to move to multiple repos sooner rather than later).