TV personality and "American Idol" host Ryan Seacrest; singers and "American Idol" judges Katy Perry, Lionel Richie and Luke Bryan; The Bachelor's Zach Shallcross after the finale; a performance from the cast of Bob Fosse's Broadway show "Dancin.'"

Professional dancers Val Chmerkovskiy and Jenna Johnson introduce new baby; actor Taron Egerton ("Tetris"); ABC News "Nightline" co-anchor Juju Chang's exclusive interview with Paul Edmonds, one of the five patients to achieve remission from HIV; Deals and Steals with ABC e-commerce editor Tory Johnson.