They've been building up a pretty sizable stable of talk-show style hosts. Not sure what kind of political satire chops Tosh, Jeselnik, or Hardwick have, but I can see Comedy Central floating the possibility of Colbert at 11:00 and one of those other guys at 11:30.

Because Hardwick's show is doing okay in the Midnight timeslot, would be my guess. Where else is Oliver supposed to go? 12:30? Prime time? Another network makes more sense.