It was mentioned earlier that Moto X will have an unlocked bootloader for Sprint, T-Mobile and US Cellular. In case of Moto X on Verizon and AT&T, Motorola mentioned that the company will not be offering bootloader unlock, instead there will be Developer editions for Moto X on these carriers.
Now, Motorola has fulfilled its promise and posted bootloader unlock for several models of Moto X. The list also includes Moto X for Sprint and US Cellular along with many other carriers across US and Canada.
Moto X features a 4.7-inch display sporting a resolution of 1280 x 768, dual-core Snapdragon S4 Pro processor clocked at 1.7GHz, 2GB RAM, 16GB internal storage, 10MP back camera, 2,200 mAh battery and runs Android 4.2.2 Jelly Bean on top of it.
Note that unlocking the bootloader will void your warranty, so be careful and think before you make this decision. Also, check the source link often as Motorola is expected to add more unlockable devices including Moto X for T-Mobile and more developer only models.
Source: Motorola