Update: Google says to expect it right after the keynote. Today, is going to be awesome.
Google just announced the Android M Developer Preview at Google I/O during the keynote. Android "M" will focus on "quality end-to-end," with a strong emphasis on improving the user experience, according to Dave Burke.
Supported devices include the Nexus 5, Nexus 6, Nexus 9, and Nexus Player. M includes brand-new features like granular app permissions, new app linking APIs, Doze mode for enhanced battery life, enhanced fingerprint support (including Android Pay), and a whole lot more.
We'll update this post as we learn more about the details of the preview.