David Letterman, one of late night television's godfathers, has a grim prognosis for the format's future, saying he'd be "surprised" if some shows last "more than a year." The one 79-year-old comedian gave a candid interview to The New York Times in which he discussed the imminent end of The Late Show with Stephen Colbert, the final episode of which will air on May 21. Letterman was not kind toward CBS for canceling 'The Late Show.' By: MEGA Paramount, CBS' parent company, made the stunning decision to cancel The Late Show last year.