The nice thing about schedules is sticking to them. HTC promised Marshmallow would come to some of its devices starting by the end of 2015, and so far the company is keeping its word. Android 6.0 came to the HTC One M8 Google Play Edition early last month, and now HTC Product Manager Mo Versi says the regular unlocked M8 will get the goods within the next 24 hours.

Getting an OTA tomorrow would mean M8 owners are getting Android 6.0 before those who own this year's flagship, the M9.

If this update is anything like what we saw on the One A9, expect a relatively stock-looking version of Sense. And after it lands, the open source kernel source files will probably arrive within a month. That will give custom ROM makers useful tools as they work on bringing Marshmallow to those users as well.