Earlier in the week Team Win Recovery Project released their custom recovery to the Nexus 6p with the caveat that it would not support encryption. This meant doing anything with the stock rom was pretty much out of the question. Today they announced that TWRP does now support Encryption on the Nexus 6p. This means you will be able to flash stock custom roms and backup and restore your stock rom. The Nexus 5X will be getting the same treatment very soon!
via Google+