By the way, currently we also allow MDB specific dead letter queue which overrides the global DLQ. We'll have to see how that works out with HornetQ.
The entire set of JBoss specific (actually JBM specific) activation config properties are here http://www.jboss.org/file-access/default/members/jbossejb3/freezone/docs/tutorial/1.0.7/html/Message_Driven_Beans.html in the second table.