The idea is one machine, one address
More like 5 IPs per computer. Each for different usages.
The only thing for sure is it is a form of ReRAM.
the fact that phase-change is a thermally driven process
When you restart your computer without a power down, you still have all that data in memory. Same difference. As for a power down, the only real benefit is it also resets the CPU and other hardware. When the BIOS starts up and copies data from the HD into memory, it already over-writes what was ever there. No changes required. If you want to take advantage of having persistent memory, then you'll need new protocols, but old protocols should continue to work as expected.