It's official: Late Show host David Letterman has decided to stay with CBS and not jump ship to ABC. Sources tell TV Guide Online that Dave signed a five-year contract with the Eye, with options to exit sooner if he so chooses. On Monday night's show, he joked: "CBS, all of a sudden, they can't kiss up to me enough — it's crazy. I finally got a get-well card for my bypass surgery two years ago... When I drop dead, there won't be this much press." More seriously, he expressed regret for the Damoclean sword that hung over newsman Ted Koppel's head during negotiations — ABC now confirms Nightline will stay put. "He is one of a very small group that represents the highest echelon of broadcast achievement, without question," Letterman said. "He, at the very least, deserves the right to determine his own professional future."