The leak comes to us courtesy of XDA Senior Member TheOrangeRemix. User response appears to be mixed, with Senior Member mentose457 initially having trouble with data and calls when not performing a full wipe during the upgrade process. However, a full wipe seems to fix these issues. And once everything was up and running, mentose457 reports the leaked ROM to be nearly fully functional.
Please note that this is intended for the T-Mobile variant of the device. Users of other variants of the Moto X should proceed with caution before flashing. Special care must be taken to modify the flashall.bat file to not flash the modem to something incompatible. If you do try flashing this on a different variant of the device, be sure to have a good backup handy and also report your findings in the thread.