Hello Heiner,
i'm not one of the WebService experts - just another user ...
In my expierience the idea to keep an application independant from the application server follows the java idea, but in reality i never seen the a project changed the server platform when in was running. So i would propose you to take the dependency to jboss - if the server will be changed really, you have to adapt your code anyway, as other app servers have their specialities too.
I dont excatly know from where jboss takes the context root, may be you check
- the service element in the WSDL
- try to use the Endpoint publish() method (see http://java.sun.com/developer/technicalArticles/J2SE/jax_ws_2/ )
Hope this helps in any way ...
Best regards, Timo