Earlier today, Polish carrier PLAY published a list of software availability for a number of smartphones. This included the Sony Xperia Z, which the carrier claims will receive Android 4.4.2 KitKat at the turn of this month i.e. somewhere between the end of February and early March.
The timing wouldn’t surprise us, given that yesterday we saw the Album app updated for KitKat support. We would expect Sony Mobile to detail KitKat rollout timing around MWC later this month, if not before. We’ll bring you official details as soon as we have it.
Xperia blog is not Sony. Doesn't the fact that they're reposting an announcement from a Polish carrier as news about a possible release date give you a clue about that? If it was Sony's official blog they would have just told us the release date.