If you are at all interested in non-SOAPy web services, you might want to take a close  look at WADL, the Web Application (!) Description Language. It is an XML based language that can be used to describe general HTTP-based service APIs that can not be described reasonably in other meta-description frameworks, such as WSDL.

Ultimately, this technology will allow web service providers (such as Amazon, Ebay, Google, Yahoo!) to focus on providing their respective services, and not on creating new APIs in a variety of languages to use these services.