Yesterday, Sony listed December 19 as a release date for Android 4.3 on its Xperia Z support page. Since then, the page was changed, and now it’s only mentioning the 4.2 update that was rolled out back in September. Still, the Dec. 19 listing should give users hopes that their handset will get rid of Android 4.2.2 soon to make way for the newer 4.3.
The Xperia Z Android 4.4 KitKat. However, this will likely happen starting next year. We'll keep you updated on the matter - faster and more often than Sony is updating its handsets.
Launched back in February, the Xperia Z is still a very nice smartphone, and you can read our review of it to see why.
Update: December 19 has come and gone, sadly without the 4.3 JB update. Let's hope this will be rolled out soon, though.