Not sure about this. I am currently building stuff on Amazon and only use the REST interface. Even when it comes to needing my own Java API, converting to Java to XML isn't a big deal anymore.
It would be good to see the proportion of SOAP/REST usage there. WS/SOAP is good but in the beginning when a lot of innovation is going on there will be some flux and supporting both would be costly.
WS/SOAP is self-documenting and can have client-side code fully auto-generated in a 100% reliable manner. REST, as it is not even near a documented standard besides "use HTTP verbs" not so much.
With the right toolkit WS/SOAP is basically automated on the server and client-side with no work involved.
Until REST gets there, enterprise applications and developers will still prefer WS/SOAP en-masse simply due to tool support.
Yeah - I'd agree in general. However, I'd argue that SOAP isn't really there yet either - it's more progressed, but issues such as versioning and lifecycle management aren't something many orgs really have a handle on yet.
So I guess my query is - How will these orgs feel about Sun moving to REST when they are still investing/maturing a SOA based on SOAP?