Update: It looks like T-Mobile got cold feet. The support page has been reverted to its previous state, showing only the Android 4.2 update from November. Sorry, folks.

Do you use a Sony Xperia Z? Did you buy it from T-Mobile? Then check that Settings menu – according to this T-Mo support page, you’re getting a taste of Jelly Bean 4.3 starting today. Of course these things tend to go out in waves, so those without patience can follow the links on T-Mobile’s site and manually download and flash the new software (10.4.C.0.797) using the Sony PC Companion software.

• T-Mobile’s Sony Xperia Z Gets An Overdue Android 4.2 OTA Update
• Ice Cream Sandwich Updates For 2011 Sony Xperia Phones Starting In Mid-April, But Carrier Restrictions May Apply
• Firmware Update 10.3.1.C.0.136 Bumps The Xperia Tablet Z WiFi Up To Android 4.2.2, Includes Support For Multiple Users, 64GB SD Cards, And More
• Leak: Evleaks Shows Off The Xperia Z1 For T-Mobile

Android 4.3 Is Rolling Out To T-Mobile’s Sony Xperia Z Starting Today, March 3rd [Update: Nope] was written by the awesome team at Android Police.