So far the Android 4.4.4 KitKat firmware update has only been released for three Sony Xperia phones: the Xperia Z1, Xperia Z1 Compact and Xperia Z Ultra. We would expect the update to come to the Xperia Z2 in due course, but we can’t be sure of Sony’s plans for the older Xperia Z series.
However, Australian carrier Optus may have given the first hint that the Android 4.4.4 update may indeed be heading to the Xperia Z. The update is listed on Optus’ “Android OS Tablet & Mobile Updates” page saying that the Android 4.4.4 update is in testing with an expected release in “mid to end July”.
Obviously this could be a mistake on Optus’ part; this kind of carrier information is never the most reliable source of information. However, there is always a slim chance of it being true. We’ll let you know if something comes of this.