It's amazing the difference I feel between reading on a tablet and an ereader. The ereader doesn't really feel like a "device," more like a book. On a tablet, I'm googling (Can you really ride from Winterfell to Kings Landing in a week? How fast do ravens fly? Lets see what the internet thinks.). They might be related to the book. They might not. Emails, HN, news…
Watching TV before bed keeps me up. Roaming the internet for half a Saturday on it makes me feel crap. Doing those with a book relaxes me, improves my sleep and my energy levels. Tablet reading is more like TV than like a book.
Anyway… I wonder if bringing that to a writing device could be some sort of improvement, at least for a subset of uses. Something that's designed to write. Editing as a secondary. Something that will feel different when you sit down to write on it. It's not research or email time. It's writing time. Change the pace. Focus.
As a second screen running your normal software… I'm iffy. As a purpose built device that is significantly different than our laptop, but possibly superior at certain tasks, I'd like to see one of these.