An incomplete version of Android 4.3 has been leaked for the Motorola Moto X; while it has been posted on XDA Developers Forum, this version of the firmware should not be loaded on your Moto X unless you really, really know what you're doing. Unlocking the bootloader on the phone, even with help from Motorola, can lead to the voiding of your warranty and the bricking of your phone...
Source: http://www.phonearena.com/news/Android-4.3-spotted-for-Motorola-Moto-X-leaked-version-of-firmware-is-far-from-final_id47648
Source: http://www.phonearena.com/news/Android-4.3-spotted-for-Motorola-Moto-X-leaked-version-of-firmware-is-far-from-final_id47648