And it's not just the PSU. The cooling of those cards will have to be much better, and your case will need to have good airflow as well.
Who knows, maybe this will make proper watercooling popular again.
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.