Per our discussion with Adrian, in 3.2.4 under config "server/all" there is going to be another deployment directory, parallel to "deploy" and "farm", which will host services that are deployed on exactly one node in the cluster.
The tentative name is "deploy-hasingleton". A service under "deploy" declared in deploy-hasingleton-service.xml will deploy the directory in question.
JMS is the first service that will take advantage of this new directory.
Any suggestions how should we name the directory and what other services are good candidates for it?
The default HSQLDB configuration should work without setting anything up.
Use another DB for persistence if you like.