I think describing a RESTful service with a WSDL-like language is a contradiction in terms.
In principle, I agree; for pragmatic reasons, I believe efforts like WADL make sense, if only to have an answer to one of the most obvious questions for new REST converts :-)
I’m not a fan of WSDL, how it looks like and its complexity. But I’m still a fan of generating client stubs and server skeletons out of a service description. If you have hundreds of services, you don’t want to implement them manually, do you? At least not the xml binding. Sometimes it’s hard to find a tool in the WSDL world which works and fits your needs, but I found one (at least for my needs). In a corporate SOA world it’s crucial to have service descriptions. And I believe even with REST it’s usefull to know which “Resources” are available, what verbs they “understand” and what data (xml-schemas or mime-types, …) they expect and return. Maybe I should have a look into WADL and the Atom Publishing Protocol.