OSB load balancing of JMS messages

Obviously, use Distributed queues.
In the Business Service creating the JMS message, enter a single URI which has the cluster address, like:
jms://host1.acme.com:8001,host2.acme.com:8001/jms.jndi.cf.MyCF/jms.jndi.dq.MyDQ

and in the jms.jndi.cf.MyCF, in the "Load Balance" tab, disable the checkbox "Server Affinity Enabled".

See also http://docs.oracle.com/cd/E28280_01/web.1111/e13814/jmstuning.htm#PERFM311