I repeat, the AtomAPI is not a Web Service. At least as the term Web Service is defined by the W3C Web Services Architecture Working Group.
Definition: A Web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.[Web Services Architecture, W3C Working Draft 8 August 2003]
You see, we need a WSDL file and a SOAP envelope to be a real Web Service. Let me be clear. That is, if not dumb, at least egotistical.
Now I don't mind the working group trying to restrict themselves to talking about a reasonable subset of technologies. That's a refreshing stance for a W3C WG. The problem that I have is the co-opting of the term Web Services. How about "SOAP Services" or maybe "RPC Services", but please if you are going to stick to just SOAP and WSDL do not use the term Web Services. What the members of the WG fail to realize is that despite their complete lack of actual authority, the W3C name and recommendations carry a lot of weight outside the standards development community, enough weight that in a couple of years someone, mark my words, will come back to the AtomAPI and rant and rave that it's not really a Web Service 'cause the W3C says it has to have WSDL and SOAP. This will happen. I kid you not. Please choose another name.
Barring any rename, which in all honesty I know won't happen, I'll just have to start referring to non-SOAP based services as Well-Formed Web Services.