Will & Grace has scored the mother of all casting coups: Pop diva Cher will play herself in an episode of NBC's Emmy-winning comedy series. One of the show's running gags has been how Jack (Sean Hayes) is obsessed with the Oscar winner and dreams of one day meeting her. Well, Jack finally comes face-to-face with his idol in the episode scheduled to air Nov. 16. Hopefully, the episode also will feature Cher getting a fashion critique from Karen (Megan Mullally).