John Hodgman is a PC, Justin Long is a Mac
You don't "sell out" to Apple; you "make art." John Hodgman (McSweeney's writer, Daily Show cast member and hobo namer) played the PC in those new "Get a Mac" ads. Thanks to everyone who wrote in saying "You mean you don't recognize him?"
Still no ID for his Donnie-Darko-wannabe costar playing the Mac, or for that cute Japanese camera.
UPDATE: Of course! Mac is Justin Long, the failed cheerleader in the movie "Dodgeball" and Warren Cheswick in TV's "Ed." Thanks again, readers — if it weren't for you, I'd have to buy a TV.