It looks like Microsoft is putting some good research into a new RESTful product, Codename Astoria.

The goal is to expose data through URI's that identify various bits of information from the service. The delivery method is provided by the application but POX or JSON are very open formats that I assume will be the norm.

Currently we have SOAP and WS-* for web services, but Astoria will allow for REST style Api calls. Microsoft will

If I'm reading this correctly, Microsoft will provide a Toolkit that is available for download. The toolkit contains runtime components that allow developers to create and consume Astoria Data Services. Currently Microsoft also has an Astoria online service that can be accessed via the internet. It provides pre-created data-sets exposed as data services. In the future it looks as if Microsoft will allow you to create your own custom data services on their site.

Since AJAX and Silverlight will probably take over the client (AJAX pretty much already has), and since Silverlight supports REST I think this project may be something to keep our eye on.

Check out the project site here: Astoria on MS Live Labs