I'm working with some colleagues to develop a way to apply Agile methods to standards development for regional and national (and I eventually hope to apply this to International) programs. It's an interesting process to consider. We don't have code to test, only interoperability specifications which makes it harder. However, it seems that many of the same principles could apply.
Use Cases and transactions become epic stories and user stories. Parts of the specification instead of the code become the items in the backlog to create and work through with the customer. Many of the same things apply, and there's even some testing to introduce into the matter (e.g., certification/conformance testing to the specifications). As a side project, I'm thinking we should write a paper about our experiences once we see how this turns out. It should be interesting. I'd love to hear your thoughts about this.