I can think of many, many times where I've called the flavor of Android that ships on Nexus phones "pure Android," and it looks like Motorola is taking a cue: its direct-sale, unbranded, unlocked Moto X will be called the Moto X Pure Edition when it ships. (The Moto X doesn't actually use stock Android, per se, but it's awfully close with a few tweaks — and the Pure Edition lacks the crapware and slower OS update schedule of the carrier-branded units.)
That "when" of the new Moto X is still an open question, though. The only guidance Motorola gave at its event was "later in September" — its website still shows "coming soon" without an option to buy or configure the 2014 model through Moto Maker, so the wait continues.
If the unbranded phone is "pure," what does that make the carrier models?