Honestly, this would be a great efficiency boost if you could figure out how to manage distributed access, even in the existing model. Content servers in the CDN could act like origins/seedboxes, and pieces could be streamed from other clients based on what's currently contained in their content cache or downloaded episodes bucket. I'd love to see Netflix do something like this as long as it was only for non-mobile clients (e.g. Xbox, AppleTV, et al). I don't mind sharing my upstream with others if it helps smooth delivery for myself.

You'd think this wouldn't work well, but if done properly it'd be at worst equivalent to the current experience (e.g. your entire stream comes only from the closest content server), but Netflix shows tend to have popularity trends so may actually perform better than the current experience because you might be watching the same show as your neighbor, just 20-30 minutes later, and this reduces load on the content servers and raises the overall throughput availability of the total network.