An article that has been in the works for quite some time has been published on IBM developerWorks. It describes how to use a message flow to automatically download a WSDL file from a remote source, extract the schema definition, compile it as a message set, and redeploy the message dictionary to a running Message Broker.
It is really great to see so much material on Message Broker (and the rest of the WebSphere family) being published recently. Do take a look at developerWorks, there is some fantastic material there.
This is my debut as a developerWorks contributor, although I should thank Ben Thompson for doing most of the work of making our idea into something publishable. Many thanks to the developerWorks editorial team, too. Look out for more from me on developerWorks in the near future.