@Pete - HTML/XML/JSON is not really part of being RESTful, however it's theoretically possible to do this already. The API only translates to/from JSON in a select few places, so you can serialise it to XML, ZeroMQ, MessagePack or whatever you want, intentionally.

(It's also RESTful, since you send updates to the same URL itself, but only for the API itself. It's intentionally self-contained at the moment, but that might change in the future.)