Normally, Google rolls out their new OS on a new device, but this year that apparently isn't the case. There are reports that Android 7.0 Nougat is already rolling out to Nexus users - and Google has yet to officially launch their new products. We do know that there will be two new Nexus devices at launch, but LG was the first to the punch with Android 7.0 and now Google is rolling it out to last generation devices before it lands on their new devices.
While Android 7.0 Nougat is rolling out now, the images aren't yet available on Google's list of Nexus Factory Images. Once they are, you can use them to flash Nougat onto your device, rather than waiting a couple weeks for the staged rollout. The new build will be available for the Nexus 5X, 6, 6P, 9, Player, and General Mobile 4G.