According to Wowhead: The Auction Houses have been decked from top to bottom with a light up floor, disco lights, a DJ booth and new music! Occasionally you as well as other dance party members of your race will be teleported to the stage gaining the [Happy Feet] buff and the stage will adorn your races main flag. You are able to use any and all toys it seems while partying in the Auction House as well so it really is a party!