The new firmware has recently appeared at PTCRB and is likely to go official soon
Last month, Sony promised that it would start delivering Android 4.3 Jelly Bean upgrade for some of its smartphones in the Xperia series and most of them have already received the promised update.The Xperia L is not among the first smartphones to be confirmed for an Android 4.3 upgrade, but that doesn't mean the device will not receive the update in the second wave.
The folks over at XperiaBlog report that a new firmware build number 15.3.A.1.12 has just been granted approval at PTCRB. The new software update will be rolled out to Xperia L models C2104 and C2105 in the coming weeks.
Unfortunately, there's no telling if this is the long-awaited Android 4.3 Jelly Bean update, but given the fact that this is an important jump in build number from the previous software version 15.3.A.0.XX, we suspect that it will bring major improvements.