Carson Daly's days as host of MTV's TRL may be numbered. According to TV Guide's Max Robins, Daly may be replaced as the network's countdown king before his contract expires in mid-2003. Daly has cut back his TRL duties since the January debut of his NBC late-night show Last Call, and the show's ratings have dropped 30 percent from 2001 among its target 12- to 17-year-old audience. For more on the story, pick up a copy of the April 13 issue of TV Guide magazine, on newsstands Monday.