Yesterday Google officially announced Android 4.0 "Ice Cream Sandwich", an upcoming update that delivers a massive redesign of the user interface and a bunch of new features. You can find a nice overview at Engadget.
Some of the highlights include an NFC-enabled feature called Android Beam, offline search in Gmail, new lock screen features and a fancy unlocking method called "Face Unlock," which uses facial recognition to ensure strangers can't use your phone without permission. Ice Cream Sandwich also includes enhancements in almost every native app within Android itself. The SDK is already available for Android 4.0, and the update itself will make its first public appearance on the Samsung Galaxy Nexus, also unveiled tonight.