JBoss.org Community Documentation
The JBoss HA-JMS service (i.e., message queues topics and supporting services) only runs on a single node (i.e., the master node) in the cluster at any given time. If that node fails, the cluster simply elects another node to run the JMS service, and the queues, topics and supporting services are deployed on that server (fail-over). This setup provides redundancy against server failures but does not reduce the work load on the JMS server node.
While you cannot load balance HA-JMS queues (there is only one master node that runs the queues), you can load balance the MDBs that process messages from those queues (see Section 18.1.3, “Load Balanced HA-JMS MDBs”).