Next X Factor Judges?

X MARKS THE DEMO: With the expected announcement that Britney Spears has been added to The X Factor’s judges panel to take her place alongside executive producer Simon Cowell and L.A. Reid, the chatter is now on who, or even whether, the fourth chair will be filled. With Cowell having his sights set on attracting a younger audience, like NBC’s surprise hit The Voice, insiders say a currently hot Disney star like Demi Lovato or Selena Gomez could be in the mix. (4/16p)