Yeah the M2 form factor also look interesting, but its a interface i cant see gaining support in the SOCs from the current makers.
Id like a M2 HDD in my next PC build too, but as things are i think it will be smarter of me to focus on a large spinning disk as i have a SSD for my OS already.
And while i have gained a little additional space by dumping a lot and put 2 old drives in a external HDD reader, then a 2 - 4 TB hard drive would be nice i think.
Just waiting for the GFX price drops they said will come soon, though on what i would like that will have to be a 50 % price drop, and that are not going to happen.
And wispers of relase of the 32 core threadripper in mid August, that just frustrate the hell out of me though i would never be able to afford a 12 - 16 - 32 core CPU, so will just have to settle with 8 and a smaller socket and chipset supporting less ram.