Given the relatively minor changes to Android that are seen on the Motorola Moto X (at least compared to the competition), the general thinking has been that Motorola should be pretty quick with Android system updates. Motorola has confirmed that its new device will get the Android 4.4 KitKat upgrade, but hasn't mentioned when that will happen...
Source: http://www.phonearena.com/news/Early-Android-4.4-update-for-T-Mobile-Moto-X-leaks_id49108
Source: http://www.phonearena.com/news/Early-Android-4.4-update-for-T-Mobile-Moto-X-leaks_id49108