If you were one of the remaining owners of an unlocked 2013 Moto X who didn't yet have Android 4.4.4, now would be a good time to check it. Looks like more folks — including us — are finally getting that latest point increase. The (aging) official changelog still states "Android 4.4.4, KitKat, is the latest release of the Android platform and includes enhanced security updates to OpenSSL," and the T-Mobile specific changelog isn't updated.
Anyhoo, we're finally updated. Enjoy.
More: Moto X 2013 forums; Thanks, Jason, Graham and Drew!