Matt Zumwalt of MediaShelf, LLC has been hard at work thinking about how to make Fedora RESTful. There is now a proposal on the Fedora wiki based on a PDF he sent to the fedora-commons-developers list.
It’s an interesting proposal. I’ve read over the PDF version quickly but it does bear a closer read.
Whether SOAP or REST is more appropriate for a Fedora API is something I’m not sure about, though I don’t mean to imply it’s an either/or situation.