According to Xperia Blog, the Sony handsets that won’t be receiving newer versions of Android are: Xperia acro S, Xperia SL, Xperia S, Xperia ion (including the LTE model), Xperia arc S, Xperia go, Xperia P, Xperia J, Xperia U, Xperia sola, Xperia tipo, and Xperia miro.
Since most of these devices were released in 2012 (or even in 2011, as it’s the case of the Arc S), users should probably not be too upset that Sony is no longer planing to update their software version.
You can check out the latest Android build that’s ready for your Xperia smartphone at the first source link below. Upcoming software updates - where available - are also listed there.
source: Sony Mobile via Xperia Blog