Curt Cagle has a nice post on Pragmatics. He puts in perspective the REST vs SOAP debate. To me the essentially part of his post is this statement:
The difference between a message-centric approach and a resource-centric approach is simply that in the first case you provide intent with the contents, while in the second you don’t (the intent is implied by the target). They both contain a formulation of state.
This post is a good read. He sums up with this:
SOAP and REST are not equivalent strategies, nor do they represent the “skilled” vs. the “unskilled” approach. Each has a specific domain where it has its strengths and should be used in that domain, just as each has its domain where it is weakest and should be carefully evaluated before being used in that other space.
Here is the original post and discussion by Don Box.