Some advertising executives have suggested that NBC's decision to fill its 10 00 p.m. time slot with a talk show hosted by Jay Leno could be a harbinger of similar moves by TV networks to cut costs. Tim Spengler, president of ad agency Initiative, told today's (Wednesday) New York Times, "Welcome to the future ... and there's probably more of this to come." Gene DeWitt, chairman of DeWitt Media Strategies, saw the new Leno program as an alternative to police procedurals that currently dominate the 10 00 p.m. hour. "This will counterprogram everything on the other networks," he said. "It's kind of putting a knife to the heart of network tradition and purists," Laura Caraccioli-Davis, head of programming for Chicago ad giant Starcom Media told USA Today . At a news conference, NBC Entertainment Co-chairman Ben Silverman said that devoting the 10 00 p.m. hour to Leno will allow him to concentrate all his firepower into the two hours between 8 00 and 10 00 p.m. In fact, when such unscripted shows as Deal or No Deal, The Biggest Loser, Celebrity Apprentice and Dateline are factored in, Silverman will actually wind up with few hours of scripted programming.