Simon says: Keith throws out a complete red herring. I don't see how the RPC spec or the encoding spec are unRESTfull, the only unRESTfull thing in the SOAP spec, is the always POST HTTP binding.

Could be true. I'm not the expert on REST I should be. But it seems to me that REST a philosophy of distributed development based on URIs and resources. Seems like loosely-coupled messaging falls right into that world - to some degree. I'm not a complete expert. Aaron Swartz, who knows more than me, agrees: "When used this way, I (and I bet most REST people) would have no problem with SOAP. Perhaps we should distinguish between SOAP-the-encoding-format and SOAP-the-RPC-over-HTTP-binding. REST people are talking about the second. New encoding formats aren't even in the same game as REST."

Of course, I am now eagerly awaiting Sam's follow up to this delicious statement: I'm now convinced that one can architect a system in accordance to the principles of REST and then implement that system using RPC style, HTTP transport, POST binding, SOAP. In fact, I'll go further and state that the GoogleSearch is an instance of this."

I hope this is true.