Sony Mobile Announces The List Of Smartphones To Get Android 4.4 KitKat :

Sony Mobile has confirmed that the Xperia range Z will be upgraded to Android 4.4 KitKat.Toutefois, no date has been announced.The list includes the Xperia Z, ZL Xperia, Xperia Tablet Z, Z Ultra Xperia and Xperia Z1.
It's strange to see that the Xperia ZR is not part of this list, as it has the same hardware as the Xperia and Xperia Z ZL. It is also a shame that the Sony Xperia SP is not on the list.
However, Sony describes it as the first series of the Xperia range will benefit from Android 4.4 KitKat.