My post is a month late but it is worth it.
Most smartphone manufacterer's follow an 18 month policy for providing updates for their phones. The WT19i is long out of the 18 month support zone hence Sony has no reason to update it, why should Sony support old phones, they want people to buy new Xperia's not stick to old ones. It sounds rough but that is how it works regardless of Google saying that it works on 512MB devices. Anyway truth be told even our ICS ran cheaply so I wouldn't expect Kit-Kat to be much better.
