Interesting thought. At that point (or for that fact - at this point) it's is essentially a reusable printable paper. For people arguing about the low resolution of the $70~ model, I would not disregard their argument because we haven't seen it in real life and would love to see how documents scale up on that display.
If you aren't using super-white printer paper, not sure that this is any more eco friendly than printing a sheet of paper off twice a day, every weekday for years. Not sure what the materials impact is for e-ink, and paper is a renewable resource and sourced from trees generally grown specifically making paper as a crop.
