1. New UI
Honeycomb’s beautiful holographic tablet interface comes to smartphones with a more appealing less geektroid system font called Roboto.
2. Improved multi-tasking
ICS gets Honeycomb’s useful scrolling multi-tasking window manager.
3. Expandable widgets
Android’s killer feature (compared to iOS at least) just got bigger. Literally. You can now make widgets larger or smaller to show more info rather than being locked to an arbitrary size.
4. Support for more media
Built-in support for Matroska (MKV) videos. Booya! No more transcoding needed for your torrented vids.
5. Instant voice
Hit the button and start talking — Android 4 can translate your voice into text on the screen as you talk not after a pregnant pause.
6. Panoramic camera
The camera app in Android has a panorama function built in — you can just sweep your handset across a scene to capture a wide angle shot.
7. Android beam
Put two Android 4 phones within 4cm of each other and they’ll use near field communication to securely exchange data such as contacts web pages etc.
8. Wi-Fi direct file sharing
Similar to Apple’s AirDrop feature in Mac OS X Android devices will be able to send files to each other over Wi-Fi without a router in between.
9. Faster web browser
10. Face unlock
Android 4 can use face recognition to unlock your phone — after a few seconds of delay. A PIN may still be quicker.