Hi Gregory,
I don't know of any delays you can configure on JBoss AS to stall the relaying of JMS messages, but you might not want to change something like that at such a level - that may impact other applications running in the same environment, and you never know which those may be over time.
There is a way to delay the execution of Jobs, however, and it's quite simple, albeit a little labourious if you need it often.
You would need to call the setDueDate(Date dueDate) method on all of the Job objects you're scheduling. Just using new Date() as the input value schedules them for right now, adding the amount of time you need for a delay should do the trick. (And for that, DateUtils in Apache's commons lang library may be helping out, or you could use jBPM's own BusinessCalendar too).
HTH!