Will Ferrell, Tracy Morgan, Molly Shannon and Norm MacDonald are all part of the talented principal cast for another irreverent, provocative season of "SNL's" trademark sketch comedy and satire -- more than two decades after the program's 1975 debut. The roster of guest hosts includes Rudy Giuliani, Samuel L. Jackson and Sarah Michelle Gellar, while Jack Nicholson makes a cameo appearance. The shows exclude some musical acts and sketches.