The 4.1.2 update features a much smoother user interface and also features an extended battery mode option for increased battery life. The update also adds the built-in HDR camera capability for pictures taken with the sensor at the cost of slightly reduced resolution (a 1MP decrease for each photo) and the Wi-Fi connection is said to be more stable than before the update.
The browser quick commands wheel in the labs section is also said to be well organized and responsive. The keyboard is also said to be improved with more responsive input and improved accuracy.
The update is available over Sony’s PC Connection desktop software as an over-the-wire update with no word on a wider OTA release.