Lasse,
Thanks for the input.
It is a performance problem and no, the JMS server would not be down.
Let's say that their is a problem with one of the queues. The MDB will still be listening for it. It will take up a percentage of processing from the app. server.
I would think, or hope to, that their would be a parameter in the MDB's data descriptor that would all me to set a number of times it would try to connect to the queue. If it hit that parameter, then it would stop the connection attempt.