that's an easy one. always reference a local wsdl file when creating proxies. The wsdl can be local on disk or in a WEB-INF folder or whatever.
The rest of this reply is my opinion.
The fact that almost all the jax-ws stacks require a wsdl xml file (either locally or from a remote http server) in order to do anything is stupid. The developer already had access to the file when he/she wrote the code. If the wsdl changes, the code will probably stop working anyhow, so what's the point? Endpoint redirection?