We're now rolling out the 4.2.2 update for Sony Xperia Z / ZL
It may not be available for all countries/operators yet but try updating using PC Companion/Update service.
Availability and rollout timing will vary by market and customer variants
For further questions regarding this update for your specific market I recommend you to contact your local support:
http://www.sonymobile.com/global-en/support/contact-us/contact-info/
