I agree with Arjen Poutsma: The role model underlying the EJB spec is very cool, and I like the way the tasks for each of the roles are described, sort of like aspects cross-cutting through the spec. Sadly, they bear no relevance to reality whatsoever.
It doesn’t help that multiple roles are expected to work with the same deployment descriptor files. Oh wait, I already complained about that a couple of years ago:
http://creativekarma.com/ee.php/weblog/comments/179/