I'm also interested in this on a basic structural level. Web-native publication allows for rapid, iterative testing and exploration of ideas—hence an accelerated evolutionary cycle for technologies, content, platforms, and formats. Independent of implementation, what are some new shapes/forms content might take?
For example, combining the basic structures of magazine and novella (Magella?) could = a medium-length series of nonfiction articles/interviews driving toward a singular narrative conclusion. Perhaps something of an ebook living on a responsive website; a blog, but with more focus and longevity.
Things along these lines that come to mind are Dive Into HTML5, Google's Think Quarterly, and Adam Westbrook's Inside the Story.