https://seekingalpha.com/article/4146816-intel-micron-moores…
Summary
The non-silicon switching technology in 3D XPoint is priceless.
Intel and Micron are dropping 3D NAND as a result.
But memory will not be the most profitable use of this technology.
The article also cites a very old article by Gordon Moore about research into this technology:
http://thememoryguy.com/original-pcm-article-from-1970/
I remember reading about Ovonics as a kid in magazines like Popular Science.