I'm most excited about the new APIs for autofilling. Using a password manager on the phone today is a pain. Password filling on webpages and native apps is wonky (to say the least), and most of the time I end up manually coping passwords to clipboard, which is both cumbersome and insecure.

I really hope the major password managers are quick to adopt this, and it improves the current user experience.

"Autofill APIs: Android users already depend on a range of password managers to autofill login details and repetitive information, which makes setting up new apps or placing transactions easier. Now we are making this work more easily across the ecosystem by adding platform support for autofill. Users can select an autofill app, similar to the way they select a keyboard app. The autofill app stores and secures user data, such as addresses, user names, and even passwords. For apps that want to handle autofill, we're adding new APIs to implement an Autofill service."