Looks really cool - but it needs real-time collaboration. If you could pull in something like Etherpad/AppJet to it and make it editable in real-time by multiple people, then I think you might be onto something.
I'm not sure technically how you would do it, literally in realtime, unless the data was pushed to the editor somehow every time there was a change - but then that could get annoying for the person actually in the flux of writing.