When I clicked through, what I was hoping for was an e-ink tablet without the battery, where you have to hold it close to an inductive charging surface each time you flip the page.

Such a thing sounds stupid at first blush, but in combination with ubiquitous inductive charging mats (imagine them on e.g. every desk in an office), it could make for extremely cheap, thin and light e-ink devices—to the point that they start being more like documents than readers: flimsy laminated 'paper' sheets that happen to be able to update themselves.

Heck, if you didn't expect to use them outside of the installation (if they were for displaying internal manifests in a warehouse, or patient charts in a hospital, etc.) then you could externalize all the "document reader" electronics, and just make the device into a dumb framebuffer that hardware in the mat can push images to. (Though you might not need to do this; we can fit some pretty complex logic inside e.g. a credit card, so we might be able to fit all the storage+firmware chips for a full e-reader inside a piece of paper without that making it less piece-of-paper-y.)