The original Moto G started a revolution for mid-range phones - specifically by introducing the idea that they didn't have to suck. Motorola is still keeping the first-gen Moto G updated, and today (or late last night), unlocked versions of the Moto G LTE in the United States started receiving the over-the-air update to Android 5.1. This was pretty much expected, since Motorola dropped the kernel source code for the update last week and tested it in soak before that.
Motorola's phones tend to stick very close to Android's open source code, especially once you get out of the flagship range. Since there are so many unlocked Moto G units in the United States, it may take quite a while for the staged rollout to get to everyone - keep an eye on your user forum of choice to see if you can find an OTA ZIP file for manual flashing. The build version is 21.11.56.peregrine_retus.retus.en.US.
As always, remember that rooted or otherwise modified phones on Android 5.0 and later will fail an OTA flash, no matter what the circumstances. Luckily the unlocked version of the Moto G is, well, unlocked, so getting back to stock won't be too difficult if you want the extra goodies and refinements in Android 5.1.