Looks like Mark Woods came to the same conclusion we did about WSDL:
“The single biggest problem I had was working out the protocol for each individual invocation and the required sequence of calls. It turned out to be only two calls, but there were many more available and I was unclear on which ones I really needed to perform. WSDL is of no help there; I think it is strictly a documentation issue.
“The Lesson I learned was that some kind of human-readable documentation, retrievable from a guessable location is really neccessary before an outsider can work with somebody else’s web services.”