Quoting "Roger B." <roger@xxxxxxxxxxxxxxxxxx>:
...it would look a lot like the sample SOAP API that Sam proposed eons ago. (Though it need not *be* SOAP... it could be an Atom-specific variation on the theme.) And if it stayed that simple, I'd start implementing it tomorrow.
You haven't written the spec in detail (essential for criticism :). Sticking to POST introduces complexity. For instance, lots of error handling is implicit in the REST design, since using HTTP verbs properly makes HTTP error codes much more useful. In POST-based API, you'd have to define fault elements for everything[1].
I guess I'm skeptical that a SOAPish API would "stay simple." That's why I'd like to see one written that matches the current REST spec feature for feature. I can't seem to locate the SOAP sample you refer to, so forgive me if it's exactly what I'm asking for.