Vsync timing across all drawing and animation done by the Android framework, including application rendering, touch events, screen composition and display refresh
Triple buffering in the graphics pipeline
Enhanced accessibility
Bi-directional text and other language support
User-installable keyboard maps
Expandable notifications
Ability to turn off notifications on an app specific basis
Shortcuts and widgets can automatically be re-arranged or re-sized to allow new items to fit on home screens
Bluetooth data transfer for Android Beam
Offline voice dictation
New interface layout for tablets with smaller screens (closer resembling that of a phone)
Improved voice search
Improved camera app
Google Wallet (for the Nexus 7)
High resolution contact photos
Google Now
Multichannel audio
USB audio (for external sound DACs)
Audio chaining (also known as gapless playback)