Today's stars can often turn into tomorrow's has-beens, and it's always an interesting guessing game to predict who will still be making an impact five or ten years down the line. Are "Artpop's" underwhelming sales numbers the beginning of a decline for Lady Gaga, or will she bounce back to her former heights with a brilliant fourth album? Can Kristen Stewart's post-"Twilight" winning streak continue, or will she cool off following a series of career missteps? Is three-time Emmy winner Jim Parsons heading for a post-"Big Bang Theory" decline, or will his star continue to rise? Check out our predictions on all these questions and more in the gallery below.