Thought parkin': one of the downsides to designing and building a RESTful application is that you have to come up with a document format for your HTTP responses. Then you have to inform all your clients what that format is. And then they have to figure out how to injest your format.
With the proliferation of webfeeds, any one of the many RSS flavors or Atom could fulfill the document format role in a pinch. There still has to be a bit of coordination on how to interpret the items in the feed, but at least you're a step up the abstraction ladder wth much less coupling of server and clients.
If you can't think of anything better, strikes me that Atom or RSS should just be the default.