In 2.1.2 we said we're working on a longer beta period for releases so bugs get caught before they reach everyone. This update delivers that: there's now a Get beta updates toggle in Settings > License & updates.
Turn it on and you'll be offered beta builds of upcoming versions before they ship. Beta builds always update you forward to the final release, and you can turn the toggle off at any time to go back to stable-only updates. If beta isn't your thing, there's nothing else in this update — sit tight for the next stable release.