Sony has been quick to announce its upgrade plans on its blog. It stated the following –

So, Sony’s Jelly Bean 4.2 upgrade for Xperia Z and Xperia ZL is well underway* – next up, Xperia ZR and Xperia Tablet Z will start receiving 4.2 from early August.

Yesterday you probably saw Google announce the next version of Jelly Bean (Android 4.3) – we’re already getting stuck in and can confirm we’ll make 4.3 available for: Xperia Z, Xperia ZL, Xperia ZR, Xperia Tablet Z, Xperia SP and Xperia Z Ultra…

We’re also looking at uplifting some of our other devices running 4.1 direct to 4.3 – we’ll share more info / deets / timings when we can, so be sure to follow @SonyMobileNews for all the latest.

So despite Sony’s previous track record with lack of updates, it seems they are trying to make amends now.