Lock screen widgets, improved launcher and new animations all included
Starting today, Sony is making an Android 4.2.2 update available for the Xperia ZL, including the North American unlocked LTE model. We just updated our own handset to software version 10.3.A.0.423 via Sony Bridge For Mac (the equivalent of Sony PC Companion), which took just shy of 30 minutes including downloading of necessary files. The update process went smoothly, and the device is indeed running Android 4.2.2 as Sony claims.
The official Sony support pages are still listing information for the previous 4.1 update so we don't have an official changelog, but our initial impressions are positive. The lock screen has been slightly redesigned to incorporate Android 4.2's lock screen widgets, including swiping left to enter the camera and right to add additional widgets as you please. Turning on and off the screen now has a subtle fade in/out animation as opposed to the circular one previously.