Dale Georg makes an interesting point:

From what I can tell, while companies are expecting vendors to have a “roadmap� answer with respect to these [WS-*] specs, when it comes time to actually implement solutions, most aren’t using anything beyond basic SOAP over HTTP with maybe some WS-Security or UDDI thrown in. My feeling is that all these extraneous specs are either going to fall by the wayside when nobody picks them up and finds a real-world use for them, or will gradually find their way into general usage both as they mature and as Web Services projects advance to the stage where the solutions they offer are required (much as is happening now with WS-Security and UDDI).

I can buy that; useful specs will get used and prosper while useless specs will whither and die. Fair enough. Here’s the problem though: SOAP itself faces an uphill battle in many places. I came from a vendor that had to produce these “roadmaps”; now I’m on the other side, considering SOAP for use in significant projects. Let me tell you, it faces challenges. Performance and interoperability (between different toolkits) are big issues. Simplicity is a huge hurdle; it’s hard to argue that REST is not more easily adopted.

The effort we put towards SOAP can go into tackling the basic issues: performance, interop, authentication and authorization, and reliability, or into esoteric issues, as we seem to be doing now. Meanwhile, REST grows. How long before SOAP itself whiters and dies?