bigger and better than ever! ET will be following along throughout the two-hour season 16 premiere to break down all the best, biggest and most surprising moments!Simon Cowell will be back in his seat behind the judges' table after missing the second half of the last season due to injury, and will be weighing in with his unique voice alongside returning judges Howie Mandel, Sofia Vergara and Heidi Klum.Meanwhile, a whole slew of new acts are risking life and limb — and dignity — for a shot at