The Federated Social Web is taking shape as people and organisations coalesce around standards (e.g. OStatus) and provide implementations of those standards. The are several efforts under way within the Drupal community to bring these technologies to the platform
We are participating in a Drupal.org group that aims to to provide a place where progress on work can be reported, ideas discussed and efforts co-ordinated.
We are also listening in to discussions in the Federated Social Web Working Group - http://www.w3.org/2005/Incubator/federatedsocialweb/