In what could be either a cunning ratings ploy or a sign of the apocalypse, five reality show hosts Tom Bergeron, Heidi Klum, Howie Mandel, Jeff Probst, and Ryan Seacrest will emcee ABC's Sept. 21 telecast of the 60th Annual Primetime Emmys. The role of glorified traffic cop is usually reserved for home-team talent (think Seacrest as host of Fox's telecast last year or better yet, don't), but rather than give Jimmy Kimmel a much-needed opportunity to broaden the audience for his late-night talk show, ABC decided to capitalize on this year's flashiest new category best reality/competition show host by putting the five nominees on double duty. ''Comedians have a terrific take, but their humor is based on making fun of things,'' explains Vicki Dummer, a senior VP at ABC, about the decision. ''We wanted the anniversary show to be a celebration of TV. It can be fun without taking shots.'' Clearly, she's never seen Probst mouth off at an immunity challenge.