Magnum P.I. to end on NBC next season / Titanic sub boosts cable news ratings / Comic-Con facing an existential threat

PLUS: Grease: Rise of the Pink Ladies creator slams "the complete erasure of our show."

Magnum P.I. to end on NBC next season
Last July, NBC saved Magnum P.I. with a 20-episode Season 5 order after it was canceled on CBS after four seasons. The first 10 episodes of the Jay Hernandez-led …