I have implemented and tested the proposed changes. Please see the patch file attached to this message.
Just checked in code in the JBoss_3_2 branch that makes the Schedule Providers cluster aware.
If run within a cluster, all providers with the same mbean name and same partition will coordinate among themselves and make sure that only one of them schedules.
As an effect if you have a schedule provider build for a standalone server and you drop it in a clustered environment, it will continue to work the same way as before. It will be deployed on each node, but only one node will provide schedule to its local manager.
There are two mbean attributes: HASingleton (boolean) and PartitionName (string) which can change the default behaviour.