In a move that will come as a surprise to absolutely no one, the losing bike design from Azeroth Choppers
will in fact be added to the game
. Currently, the winning Horde-themed bike will be given, for free, to any account that logs into the game before September 30th. The Alliance bike, however, will be added to the game sometime after the launch of Warlords of Draenor
, and be available for in-game purchase.
Blizzard is being coy on the subject of cost, but their article emphasizes that it will cost "a pretty hefty sum of gold," so if you want it, best start saving now.