To summarize, the Xperia Z, Xperia ZL, Xperia ZR, Xperia Tablet Z, Xperia SP, and Xperia Z Ultra will be getting Android 4.3. There’s no concrete dates given; and remember, the Xperia ZR and Xperia Tablet Z has yet to upgrade to Android 4.2 (this will take place in “early August”).
Sony has also said that it’s looking to bring some devices straight from Android 4.1 to 4.3 - again, no timeline is given.
For Samsung, HTC, and LG, TechRadar reports that they’ve no concrete info to share at the moment. It could be “soon”; it could be “in the coming months”.