This is already implemented and under testing in jboss 3 from cvs. Be aware that the configuration system in jboss 3 is still undergoing substantial changes.
Take a lookat MVCSoft Persistence Manager. It replaces JAWS and is fully CMP 2.0 compliant. I have it working with JBOSS 2.4.1 currently. Its not free ($199) but its definetly worth the money. They'll give you an eval copy if you like. See www.mvcsoft.com