I'm not sure who did it first, i first heard similar technology coming from AMD. A quick search found some articles such as;
http://wccftech.com/amd-working-hynix-development-highbandwidth-3d-stacked-memory/And for quantum computing, i suppose if we had a true quantum processor able to emulate conventional computers software (base 8/binary), i believe that could indeed throw a wrench in current encryption of all kind.
But such computers would be qualified strictly as military grade for the long foreseeable future, hopefully it would be done gradually as a sudden jump in technology always cause much chaos.
HBM isn't comparable to 3D Xpoint because it is just not as fundamentally different to what we have today. However, it is much better than GDDR5. To simplify: "High Bandwidth Memory (HBM) is a high-performance
RAM interface for 3D-stacked DRAM memory from AMD and Hynix. "HBM gen. 1 has already been released in commercial products (AMD Fury), and HBM gen. 2 is coming very soon.
As the image clearly shows the benefits for GPUs are there and we are supposed to see generation 2 products in 2016.
Update: Some corrections.
I see, i'm not sure how "fundamentally different" it is, it actually sound like it is just an evolutionary technology over AMD's HBM, for memory.
3D Xpoint is a still-in-development-phase technology true, but also happen to be coming right after AMD's HBM.
It seem to me its Intel's project to keep in the race.
The main article itself(
link) mention the technology is also basically stacking chips on top of one another. Though i suppose i'll need to wait for a proper comparison of the completed systems to further comment.
I just very much doubt it will stop at Ram for AMD and non volatile storage for Intel.