The New York Times reports that Sudeikis' stay may just be through the election, quoting showrunner Lorne Michaels:
“Right now the idea is that Jason will go through at least until January,” Mr. Michaels said. But he did not foreclose the possibility that Mr. Sudeikis would be around for the full season. “He’s a fiercely loyal guy, both to the show and to me,” Mr. Michaels said.My guess? Sudeikis stays through the election and inauguration if Mitt Romney wins. With the cast turnover its facing for this upcoming season (Abby Elliott also left), SNL isn't in the best position to find a new Romney with the presidential election hitting the home stretch.