One more familiar face is leaving Saturday Night Live: Jason Sudeikis won't be back after eight years as a performer and two before that as a writer. The actor made the announcement on the David Letterman show that taped this evening and will air later tonight, reports ET Online. "I'm definitely done," he told Letterman. "I'm not coming back next fall." Sudeikis said he almost left last year, but Lorne Michaels convinced him to stay because he was the show's Mitt Romney impersonator. Bill Hader and Fred Armisen previously announced they weren't returning.