I spent some time looking into the state of the Pacemaker/Corosync integration today and I can only recommend Pacemaker users stay on the previous version of OpenAIS (aka. Whitetank).
In a nutshell, shutdown is utterly broken.
r2140 of Corosync removed the shutdown worker thread which allowed plugins such as Pacemaker to continue sending and receiving cluster messages.
Without it, Corosync waits for Pacemaker to finish and Pacemaker waits for the messages it tried to send to arrive and be acted upon. Needless to say no-one makes any progress.
Stay tuned, now that integration testing has started it shouldn’t take too long to get everything sorted out.
Update
Since writing this, the necessary testing has been done and Pacemaker is now supported on Corosync provided you have
corosync >= 1.1.2andpacemaker >= 1.0.6