The biggest feature to hit the Android keyboard in 4.2 is gesture typing, where you swipe across letters to write words, like Swype. Well, if you were wondering how it worked, you can try it out now. The full Android keyboard is available for download for almost any Android 4.0+ unrooted phone.
To install, you need to have any phone running Ice Cream Sandwich or above that is NOT stock Android. So if your phone came with an unmodified build of Android, you’re out of luck performing this without root. But if you have a manufacturer skin, like TouchWiz or Sense, you can easily use this. Just download the keyboard APK, install it like a normal app (with install from unknown sources enabled), and enable the keyboard in settings. You got yourself the 4.2 keyboard!
If you are running AOSP or can’t install this APK, you’ll have to go the rooted way. Do this at your own risk, as it could be dangerous. Do a full backup, download this ZIP, and flash it in recovery. Quite simple.
The keyboard works well. With TouchWiz devices (and possibly others, this is from my personal experience on TouchWiz ICS on a Galaxy S II), there is unfortunately no tap to correct. But the swiping works well, and is fairly accurate. There is some lag in the trail animation, though there is no lag in actual input. Go try it out and tell us what you think!