I'm interested in this as well, but so far I haven't found a way.
The JBoss J2EE deployment descriptor XSD which includes the POJO Service deployement descriptor does not seem to allow for arbitrary management properties, however.
I also tried the using a -service.xml file as describe in this thread, but there was no magic - I ended up w/ a ordinary MBean, but the EJB didn't get deployed.
Seems like this is needed. I really like how this ties together the actual service w/ the mgmt interface, but without the attributes I can't use it in a lot of places. Shall I put in a request via JIRA or is there something we're not seeing?