The "Stronger" singer isn't the only Idol alum switching over to NBC, either. Jennifer Hudson, who competed on Idol during its third season and somehow didn't win, will be joining Shelton, Adam Levine, and Miley Cyrus as a judge on The Voice this season. Though they may not be coaching alongside each other next spring — the full cast has yet to be announced — Clarkson said she'll be watching Hudson work her magic.