The Sony Xperia Tablet Z came to market with Android 4.1.2 on board; but the word from those with the LTE variant of the slate (SGP321) is that it is being updated to Android 4.2.2. The firmware build being used on the tablet is 10.3.1.A.0.244 which is the same build of Android 4.2.2 used on the Sony Xperia Z handset, Sony Xperia ZL and the Sony Xperia ZR...Source: http://www.phonearena.com/news/LTE-version-of-Sony-Xperia-Tablet-Z-receiving-update-to-Android-4.2.2_id46067
