When I heard about SOA (http://www.sun.com/products/soa) for the first time, I considered it a really great approach. I had just two doubts about it. I was pretty sure, a lot of functions within the enterprise IT infrastructure at the vast majority of potential customer sites were not ready to be accessed via web services. And the second one, well, it was really hard to believe, that every single existing web service in heterogeneous IT infrastructures, which was (and still is) quite usual at customer sites, could smoothly start communication with each other, without certain testing and possible additional configuring.
Now I am quite happy that I can contribute a solution. Project Tango, which I am part of, addresses both of these issues by introducing not only the implementation of appropriate interoperability standards but also the tooling for it. Detailed information about emerging WSIT (Web Services Interoperability
Technologies) can be found on http://wsit.dev.java.net/ site.
And because seeing is believing and hands-on testing is even better, I really recommend you visit JavaOne 2006 LAB-4335
hands-on session, which will cover an end-to-end example of all of this amazing stuff.