Introducing Android 4.2, A New and Improved Jelly Bean

Android Jelly Bean 4.2 (Jelly Bean) SDK

Is available for download now.

Highlight include Renderscript computation directly in the GPU on the Nexus 10, interactive lock screen widgets directly on their device lock screens, support for external displays that glets you target unique content to any number of displays attached to an Android device, and enhancements for international users.

Download the Android 4.2 Platform from the Android SDK Manager. For a complete overview of what's new, take a look at the Android 4.2 platform highlights or read more of the details in the API overview. 

What are you going to build with these new APIs?

Link: http://android-developers.blogspot.com/2012/11/introducing-android-42-new-and-improved.html