Twitter is not a protocol, any more than Windows or Myspace or Symbian are protocols. Twitter is a proprietary platform under the control of a single company, and treating it as a protocol is dangerous to both companies and their users.
The internet was pretty closed when DARPA owned it and so TCP was proprietary. Fortunately it became ubiquitous, was written up in an RFC and we can all inter-operate now.
Distributed blogging you say. Sounds like this newfangled NNTP protocol I just read about might be just the thing. Maybe I could build a startup around that
Twitter as a protocol is pretty stupid. It's trivial. Also, as a messaging protocol, it sucks. 140 characters? :/
There's far better more widely used communication protocols out there, and new ones being made all the time. Difference is Twitter has a fantastic hype machine.