First, this is a fantastic idea - well done.
I'm exploring ideas for the back-end of a distributed social network. I wonder if there are any reasons that the existing and planned protocol that you've developed wouldn't work for this.
The idea involves users having their own server and storing their own information & files. Nothing would end up on your server without agreement.
Various rules generated from the social network layer would be implemented by reconfiguring the sync backend.
For example, 'following' someone would mean accepting a one-way, filtered, synchronised folder from their server. This would then be displayed on their home page etc.
Do you think this type of setup would be a suitable application to run on top of ClearSkies?
Andrew