[davewritescode]

Most of the problems with message queues are from the fact that you will eventually get messages that you can't process now but might be able to later.

Depending on your requirements you either stop the state of the whole system or use something like dead-lettering and/or delay-queues + retry count headers to make sure that you can reprocess failed messages without letting them accumulate until you're wasting CPU processing messages that will never work.

The other problems with message queues is that you need to make sure you have alerting on all your queues otherwise you're just waiting for trouble.