American Chopper and World of Warcraft. The first episode is out now, and you can guess the heart of it just from the premise. Two bikes will be designed -- one for the Horde, one for the Alliance -- and fans will vote on which bike winds up in the game as a mount.
The first episode, of course, is very much the proof of concept; it features a very early glance at the starting point for both bikes as well as a discussion of Horde and Alliance aesthetics. You can watch the whole episode just past the cut. It's going to be running at least through the end of May, so you'll get a front-row seat to see both choppers brought from concept into execution.