We may still have a six-week wait until Sony officially releases the Android 4.1.2 Jelly Bean update for the Xperia S (LT26i), but if you want to see what’s in store then you’ll be glad to hear the firmware has leaked. Firmware version 6.2.B.0.68 brings with it Android 4.1.2 and a new 3.4 kernel to the handset.
As with any leaked ROM there are a number of things that do not work including the ability to get a network signal, so only download this if you want to try the new features. It is developer firmware that has been ported to production devices and therefore will only work on phones with an unlocked bootloader. You can install this using recovery and full download links are at xda-developers.