It becomes even more complex if you want to use specific versions of services on the ESB. Where is that configured, if at all? I do not know enough of the JBoss ESB to answer that myself.
jBPM also has versioning of forms (deployed with the processarchive). There seems to be a small issue with that atm (versioning not realy working) but in real life applications it is not enough to just use the forms. Using a real (seam based) webapp is. But how to deploy 2 webapps on the same url (customers should not know which version they are using, the want to use webappA
These are from real life experiences with JBoss jBPM, but the same has happend with Bea in combination with Staffware/Tibco the problems are the same (in fact even worse)