Sony today announced that starting this week it will begin rolling out latest Ice Cream Sandwich (Android 4.0.4) firmware update for Xperia T and Xperia TX. The new update adds screen mirroring through Miracast; provided you have a WiFi enabled TV or Sony recommends the Netgear dongle (PTV3000) for those TVs without built-in wireless capabilities. The update also include Extended Standby Mode feature that shuts off WiFi, or data traffic temporarily and most applications become inactive when screen has been in sleep mode.
The upgrade also brings new improvements to Sony’s media applications – a movie app with a small viewing window, controls and film gallery, photo album makes use of Sony's full image processing engine and HD Voice support for Xperia T (but not Xpeia TX)
Source:- Sony Blog