I am not sure how this proposal deals with the problem of templating. If you have a bunch of documents (say, blog articles) that should have a consistent layout, you are going to want to create a template for them. But then the document you see isn't the "true" document, and in order to save the content you're going to have to annotate it to "reverse" the templating.

If it does this, then it is very exciting indeed, but I could not see it.