Sony has already revealed that they will be rolling out Android 4.3 Jelly Bean update for numerous of Xperia devices this month. Unfortunately a week is over and no updates from Sony has been rolled-out, but a published report out of Asia shows what allegedly is the Android 4.3 update for the Sony Xperia ZL.
As you can see, the screenshots shows the UI of Xperia ZL, after 4.3 update, has changed from black to white, similar to that used with the Xperia Z1 and Xperia Z Ultra. The image reveals the firmware version as 10.4.X.X.X.XX.
There is no word on when the update will be rolled out officially, but given Sony's statement, it won't take much longer.
Source - Gfan
Via - Xperia Blog