I think there is a class of device here that is missing. Low power but forever devices that have some basic functionality. Over time I could see this taking over laptops and the like as ultra-low-power became more and more capable.
On that note, whatever happened to netbooks? As someone who writes a lot and need a mobile device to do it on, they used to be perfect. Can't seem to find the form factor anymore. Even the smallest Chromebook seems only slightly smaller than a laptop.
I'm pretty sure the battery packs in both of them are just some 18650 in a trench coat, so at some point I'll probably attempt to replace them and hope I don't start a fire