You can buy FRAM (Ferroelectric RAM) which are effectively the same thing just in smaller package. But I have seen them only about few kB. However the amount of R/W operations is effectively unlimited,
Phase-change memory is the most advanced high-endurance nvram, with Intel and Micron's XPoint being the most advanced to have hit production. If it had stuck around long enough for the RAMpocalypse, they'd probably sell out their production capacity.
It is the future, and has been the future for almost 40 years already! I bet that's what the hoverboards will use inside their microcontrollers — gotta drive those portable fusion reactors reliably!
One of our product use msp430 FRAM version to store the motor position, due to high sampling rate, if we use flash we would burn through flash in no time. The FRAM is really neat.
Yes, although (like some flash technology) read cycles are slower than write cycles, and it takes longer to read a 0 bit and than 1 bit (or vice versa).