I'm wondering the same thing, where is the ota for n6...yet the guy posted that scrshot claimed it's updated from official OTA...
Well, supposedly Google's normal OTA staging starts with a push to only a 1 percent sample before ramping up. Maybe that guy was in it.
But so far I am unaware of any OTA being reported in the wild and captured with a link. The factory image for MMB29K has been sitting on the developer page for several days now. Sprint even announced an OTA rollout to that build but no other carrier matched it. So far no one on any carrier has reported receiving the update.
Maybe Google discovered something wrong and is holding up the rollout.