The plan is to host CMSSW on http://github.com
by summer 2013.
Evolving FAQ for the process
No vendor lock-in, git distributed design allows safe & easy
migration from one hosting service to another.
We will have read-only mirrors at CERN and FNAL which can become
master if needed.
Git is fully distributed by design, however there will be
one main, authoritative CMSSW repository