Very cool tech. But I'm sure this will just sell due to it's novelty, kinda like 3D TVs a few years back.
I will always prefer a large iPad Pro with a phone than a large tablet that can fold into a phone that will still be too large in phone mode but then probably too small in tablet mode.
Eh.... imagine an iPad Pro, that you can bend and split the screen, basically making it a binder. You get one screen on front for a cover, and then 2 separate screen to have 2 pages, much like a book.
Getting Technology that better replicates paper, effectively disrupts the need for paper. As we head towards a paperless world, this is a godsend, and the applications of this technology can really put a final step in overtaking paper. Plus, even for something like a iPhone, it means you would be able to fold your iPhone, making it smaller much like a wallet.
It being foldable, will eventually mean that more places will be foldable as the tech progresses as well. Imagine a display in which you can fold the display in whatever way you want. It really is a huge leap in phone and tablet technology.