السلام عليكم أخ أحمد
The KitKat update is available in KSA since last week, but you cannot do it with the phone by itself. You need to do it through your computer and the PC Companion software.
Yet, I don't think it's a good idea to get the update immediately, as several users have been reporting issues with notification sounds, audio playback, camera button functioning and quick battery draining. These issues have been encountered by users in Saudi Arabia as well. You can check them on the ADSL Gate website if you want.
I prefer to wait for Sony to release an improved version of the update, and I advise you to do the same.
Peace.
