There is no way using JBoss AOP. Once you start changing classes used by JBoss AOP itself at runtime (since everything is dynamic) you could end up with some very strange and unpredicatable behaviour :-)
O.K, thanks for your quick reply!
Is it also impossible to intercept methods of subclasses of classes in javax.*? For example, I'm trying to intercept the onMessage() method of each implementation of javax.jms.MessageListener.
I'm currently running into a NPE while doing that, see http://community.jboss.org/thread/166947?tstart=0