Social Stream was presented at the Federated Social Web summit 2011. It was a wonderful event, with a lot of smart people doing very interesting things and discussing cutting edge ideas.
We introduced our work with Social2Social, and the privacy problems we experienced when we tried to implement federation using OStatus. Evan Prodromou was totally receptive, he commited to work on privacy issues in the next version of the standard. In the meanwhile we probably take a look to solutions using XMPP, like OneSocialWeb or buddycloud.
Concluding, there were three wonderful days meeting amazing people. Hope see you soon!