As I put in my what to expect from the Google event post yesterday, the company announced today that Android Marshmallow will start being delivered to existing Nexus devices starting next Monday, October 5th. This date was somewhat confirmed prior to the event thanks to leaked documents but with it being official from Google, we are set.
The devices that will be receiving the update OTA starting Monday will be the Nexus 5, Nexus 6, Nexus 7 (2013), Nexus 9 and the Nexus Player. The Nexus 4 and the Nexus 7 (2012) will not be receiving the update as I posted yesterday which has caused some anger, particularly for the Nexus 4.
Users of devices should expect to start seeing the OTA updates to Android Marshmallow coming to their devices over the course of the next week. Not everyone will be updated on Monday as Google tends to roll these out in phases. For those of you who have rooted devices and want to install the update manually, the factory images should be available on Monday as well.
There are a lot of changes coming in Android Marshmallow that will benefit users including Google Now on Tap, Doze for battery saving, and improved permissions handling.
When other devices like those from Samsung and HTC will be updated is still unknown. We have a pretty good idea of which devices will be updated but when they will start actually rolling it out is unknown but likely will be several weeks or months after the initial release.