This is not official but soon to be! The Android 4.3 firmware version for Xperia Z and ZL respectively by XDA legends DooMLorRD and Androxyde in the “Commercial & Journalist".
Here's some changelog update for Android 4.3:
- White UI just like what Xperia Z1 has on Android 4.2.2 firmware.
- New Camera app similar to Xperia Z1.
- New Xperia home 6.1.2.A.0.1 version.
- New Album app 5.2.A.1.26 version.
- New Movies app 5.3.A.0.18 version.
- New themes and wallpapers just like Xperia Z1.
- You can choose new themes now, as there is “+” option tapping on it, you can download some cool themes from Sony Select app where the navigation bar and status bar color changes like to “blue” and the soft keys icons also.
- New keyboard app.
- No X-Reality for mobile, same old Bravia Engine 2 is there.
- Performance enhancement and Bug fixing.
- Screen calibrated for more brighter display.
- Battery life, need to test it.