We recently published a preview download of the next release of our SOA platform: I'm very proud of all the hard and innovative work that our team has done on this project. The project was a real team effort from its inception. It brought together some of the brightest folks in our middleware organization. I am convinced that nothing else in the industry comes close to combining the key elements of technology required for a SOA deployment into a single, integrated platform.
We use the Service Component Architecture as the overarching model for application development: it ties together process orchestration, declarative XML transformation and routing, human workflow, business rules, and sophisticated policy management. I like to think of it as an "application server for integration": a service platform that supports domain specific languages and technologies required for integration and SOA scenarios.
Download it and try it. I think you'll be impressed.