That sounds like a fun project :).
1. On the trunk you can find a quick start that shows how to do a synchronous request (webservice_war1)
2. I think you need both ESB and jBPM in an integrated way. Maybe you can help us making an example. It's pretty straightforward, but we just have not gotten to it.
I think I answered all your questions, but ask them again if I didn't :)
cingram - an ESB would be a great place to start creating re-usable services, such as the one you describe.
JBossESB does not yet have integrated jBPM, that is something we will be working on post 4.0GA due out shortly.
JBossESB does support a "synchronous" style of messaging, which could be done using a 2-Way Courier which will handle getting a response for you. The Trailblazer and I think some of the other examples can show you how this is done.
I suggest you start by looking at the QuickStarts and the Trailblazer which should give you a good idea of the features available with the ESB, and will also help you visualize how you could design your service in the context of a central SOA deployment for your services.
Come back to the forum for more help at any time.
As both Kurt and Daniel say, we're looking at jBPM+ESB integration now. There is an example in progress, but due to time limitations it won't make it into the GA release. However, it should be released pretty soon afterwards.
Thanks for the replies! The JBPM isn't a breaking point for me. Once I have my service bieng called I can then have the service delegate to the JBPM for the actual one to be invoked. That to me is the easy part. I will start looking at the suggested examples immediately.