Instead of one new Nexus device, this year we're getting two: the Nexus 5x and the Nexus 6p. But as usual, what's perhaps more exciting than the release of a new Nexus device is the software that comes with it. When Google shows off the devices, which we expect to happen on September 29th, they will show off the final version of Android 6.0 Marshmallow.
According to Canadian mobile provider Telus, it looks like the OTA updates will start rolling out to the Nexus 5 and 6 soon after. How soon? October 5th.
Note, that's just the potential start date. The rollout could take weeks, but Google is generally quick to release factory images and OTA zip files that you can install manually if you rather avoid the wait.