Superman

July 3, 2006 -- IS Brandon Routh already getting too big for his tights? The "Superman Returns" star agreed to do the countdown on tomorrow's NBC "Macy's Fourth of July Fireworks Spectacular" but backed out last week. Our miffed NBC source sniffs, "He was signed, sealed and delivered last week. But then all those glowing reviews of the movie came out and his people called and canceled . . . We're [upset]. He's a newbie - he shouldn't be burning bridges already." But Routh's spokeswoman claims the latest Man of Steel was never confirmed to do the fireworks show. "I never even received a request," she says. "He is going to be in Daytona for the Pepsi 400. That's been planned for months." In any event, NBC News second-stringers Lester Holt and Campbell Brown have been drafted to do the countdown. Liza Minnelli, Lionel Richie, Nick Lachey and Bo Bice are slated to perform.