This FeedHose thing is starting to get interesting!
4. You can also get the long-poll version in JSON, though it's harder to demo. You should call this from a loop in a script to test, or from a browser-based AJAX app. The call below will timeout after 3 seconds. The default is 180.
5. The seed page is also available in JSON. (I've got a general-purpose JSONizer inside the app.)