Is there any tool allowing to generate DataContract entity definitions based on a JSON sample? I'm really missing the old good WSDL metadata with code generation facilities.
Yes, you can find such a tool at http://jsontodatacontract.azurewebsites.net/. There's a post about it at http://blogs.msdn.com/b/carlosfigueira/archive/2011/01/11/inferring-schemas-for-json.aspx.