Motorola bit the "developer edition" bullet, and is planning to launch a 32 GB Developer Edition variant of the Moto X. The Developer Edition could feature an exclusive design that can't be further customized using Moto Maker, more so because it comes carrier-unlocked (Moto Maker is AT&T-exclusive).
Moto X Developer Edition will feature an exclusive piano-black front bezel, and a white crosshatch back panel, with "Developer Edition" markings. Apart from its carrier-unlock, its biggest feature, of course, is the unlocked boot-loader, which lets you tinker greatly with the phone's software, even letting you toss out the stock software for practically anything of your choosing.
Motorola ended its Developer Edition teaser with a cryptic "coming soon" note, with no other details.