1. You can add your own JMS properties to the message and do your own expiration. The checking would have to be done by the MDB, in the onMessage method.
It might be useful to create a JBoss vendor JMS property that delivered expired messages to a specified queue, but I haven't heard of much demand for it.
2. In JBoss 3.2.2RC1 you can schedule delivery of a message at a particular time.
Thanks. Do you know by any chance when 3.2.2 will be released?