JAX-WS RI now sends the server side stack trace over the network
One of a very common problem that people (especially new people) faces in the remoting system like JAX-WS is this. Your server throws an unexpected exception. You get an error on the client saying "server reported an error", and you'd like to better find out what's going on in the server, but you don't know how.
So to make the JAX-WS RI easier to use, I just implemented a mechanism where the server side exception stack trace (complete with all nested exceptions) is captured in the SOAP fault message. This allows the JAX-WS RI client to reconstruct the exception, and so when you dump the exception on the client side, you'll see the complete stack trace on the server.
This change should be in the final release of JAX-WS RI 2.1, which should be "soon."