Justin Bieber, Christina Aguilera, Cee Lo Green, OneRepublic, 2011 "Idol" winner Scotty McCreery and Jennifer Hudson headline the 28th annual holiday extravaganza at Disney's Florida and California parks. Nick Cannon, Mario Lopez and Maria Menounos host the program, which also features "A.N.T. Farm" star China Anne McClain and her sisters; singers Nathan Pacheco and Katherine Jenkins; Marlee Matlin; and ABC Family's Katie Leclerc and Sean Berdy; as well as Disney characters and Muppets.