In order to continue the evaluation of JBossESB, I would be pleased if this issue could be clarified.
At the moment, there's no way to override the endpoint address defined in the WSDL.
There is a short-term workaround that you could use until we make it possible to override the target endpoint address (http://jira.jboss.com/jira/browse/JBESB-1795).
The workaround would involve you overriding the SOAPClient and reimplementing the invokeEndpoint(String request) method slightly. In the first few lines of this method you'll see how it gets the endpoint address from the wsdl. You could change this to get it from an override config parameter. The rest would be exactly the same.
Is the fix for this issue contained in the latest JBossESB v4.4.GA release ?