list of features for 4.2
New mode called Photo Sphere - New Photo software Photo Sphere lets users take 360-degree photos with Android 4.2. It also allows users to take full 360-degree photos composed out of stitched images. Also, the composite images can be viewed right on the device and shared on social networks, and can post them on Google Maps.
There is now an improved on-screen virtual keyboard - This new keyboard features Gesture Typing. It's basically Google's take on Swype with upgrades. This new software automatically adds spaces and can predict the next word you are trying to type. Additionally, voice typing is improved. You ca speak your messages out-loud and the software can convert them to text even while offline.
Now includes multiple user support, and enhanced keyboard features (this feature is for tablets only) - Interestingly, the code for this feature was already in 4.1 but Google only just now "activated" it for users. Google indicated, "Everyone can have their own homescreen, background, widgets, apps and games – even individual high scores and levels! And since Android is built with multitasking at its core, it’s a snap to switch between users – no need to log in and out."
Android 4.2 Now includes wireless mirroring on any TV that is connected through the same Wi-Fi. This allows a user to display anything from your on your device's screen onto your HDTV, like YouTube, movies, pics and websites.
The final new feature is called Daydream - this new feature attempts to "jazz up" your lock screen. It basically displays entertaining or useful information (like your own personal photo album, or favorite headlines) while your Android is locked or idle.
taken from DF.net
Wifi TV mirroring will be so sick. too bad i dont have a smart tv