Just a few days ago Motorola was among the first to announce it will update its most recent phones (Moto X included) to Android 4.4 KitKat. The schedule is yet to be revealed, but the first leaked Android 4.4 ROM for T-Mobile's Moto X is now available for download.
The KitKat ROM popped up on XDA Developers yesterday and seems to be a dump from a developer edition of Moto X. It is stable enough for work though there are some bugs and features that still have issues. You should carefully read the thread before installing the ROM.
You'll need an unlocked bootloader in order to install the KitKat ROM. And the update may - and probably will - cause you to lose your root access. Hit the source link below for download links and installation instructions.
Meanwhile, there are rumors that Motorola will include T-Mobile USA this Friday into the Moto Maker website and its subscribers will be able to make their own custom design of the device. Right now the Moto X is available only in SIM-free option and only in black and white flavors through Motorola.
when will Samsung announce which phones will be updated to KitKat?? is Galaxy S Duos going to be updated?? as google claims that kitkat runs very smoother on old devices than ICS o JB ....
already available for Sony Xperia Z - http://www.xperiablog.net/2013/11/05/android-4-4-custom-rom-hits-the-xperia-z/
im waiting android 4.3 for note 2 also. the official date should be by the end of this month. hopefully it is true.