Having recently reviewed an excellent bit of solution architecture from one of our excellent Principle Consultants it struck me thta a key aspect of SOA is the need to provide a registry of services. Now this may sound like a simple list or datadase solution but what really 'lit my fire' was the use of the rules engine as the registry. What a cool idea - we can use the content of the message passing through BizTalk 2004 to decide the services it requires to fullfil its process. So what we end up with is a way in which we can bring on, change, replace services and fulfil our desire for SOA.
Nice one Arch Hacker!