Just did some updates on the o-push website to reflect its status. To sum it up, it's going pretty well.
The bad thing about server side software is you cannot show a screenshot. Will try to make a screencast of a working synchronisation.
Next o-push task is storage implementation : storing device ids, client and server mappings (obm database id to pda identifier). Right now this is stored in memory, but as we plan to integrate o-push in OBM 2.3, I'll use PostgreSQL tables for the persistent storage implementation.
On the MiniG front, Adrien just committed lots of work on iCalendar invitations. When you receive an event invitation, you can accept it and the event will be created in OBM (or updated if it was already coming from obm). In my opinion, one the nicest minig feature with event invitations is the "has:invitation" search tip to find your pending event invitations.