Looks a like minor bug-fixer type update is available for the Sony Xperia S.
Dubbed in version number 6.1.A.2.50, the update looks to be a small update to the current software version running on the Xperia S, version 6.1.A.2.45, and is still based on Android 4.0.4 Ice Cream Sandwich.
Check your device’s settings for the over-the-air (OTA) update notification. It may not be available for all Xperia S owners and could be a country specific update only, so if you don’t see a update notification then sit relaxed and wait for the real thing, that’s the Jelly Bean update.
Obviously we’re all waiting impatiently for the Jelly bean update for the Xperia S but Sony hasn’t announced anything promising yet in that regard. And unlike Acer, who’s pushing out Jelly Bean update for the Iconia Tab A700 without giving a prior announcement to the owners, its Sony’s very part of upgrading its devices to newer versions.
So make do with these minor bug fixing updates Xperia S folks, while waiting for an announcement for the Android 4.1 Jelly Bean update.