Most of the energy in this space has gone into http://tack.io/ which has been called "a non-controversial first step" - I believe it is making its way though standards talks at the moment although I have not looked into it for a while.

Personally I think now is good time to revisit assumptions made a few years ago - security and privacy and in particular non-government controlled systems are on many peoples lips.

If I ever clear my current plate, I would be interested in diving into the problem.