Much of the OpenSocial feature set that we would like to include in Rave will probably depend on the OS 2.0 work that is going on right now. To the best of my knowledge, OS 2.0 should be supported (mostly) by Shindig 3.0, which currently resides in trunk. If there are no objections, I will move the dependency to their 3.0 SNAPSHOT this weekend.
-Matt
