JBoss hot redeploys EJB/EAR exploded as folder only in the case when EJB/EAR has deployment descriptor.
Touching deployment descriptor actually causes JBoss AS to redeploy the module.
Changing just .class files does not cause.
Therefore, solution is to have stub deployment descriptors within the project.
reported this bug in AS 5 anywhere ? You should be able to trigger redeploy without having deployment descriptors...