Android 6.0 Marshmallow will come with the new Nexus 5X and 6P when they arrive next month, but part of the reason people like Nexus devices is that older models get quick updates too. Google announced today that Marshmallow updates for the Nexus 6, Nexus 5, 2013 Nexus 7, Nexus 9, and Nexus Player will begin rolling out next week.
Unfortunately, Marshmallow drops support for the aging Nexus devices from 2012: the original Nexus 7, the Nexus 4, and the Nexus 10. Those gadgets should continue to receive security patches under Google's monthly patch program, and they'll keep getting app updates through Google Play for the foreseeable future (hey, Android 5.1 is still newer software than most Android devices are running right now). But if you use Nexuses so you can run the latest version of Android, it's the end of the road for these models.
Some of that hardware, particularly the 2012 Nexus 7, was already having trouble with the newest software, so this move may be for the best. All three have had around three years of full software support, which is a fair amount of time even for Nexuses—the Galaxy Nexus, Nexus S, and Nexus One all received updates for a little under two years.
Our full review of Marshmallow will be posted as soon as we can spend some time with final versions of the software. If there are any particular issues with Marshmallow on older phones and tablets, we'll report on those as well.
Update: One thing we didn't hear about was the fate of the Google Play Edition products, which Google completely stopped selling early this year. We've contacted Google for comment and will update the article if we get a response.