Jay Leno is expected to draw huge ratings tonight (Monday) for the launch of his Jay Leno Show , with Jerry Seinfeld as his first guest. The question throughout the industry is, how big will those ratings remain as curiosity fades in the days and weeks ahead, and will they cannibalize the Tonight show's, with Leno's successor, Conan O'Brien. Commenting on the debut, Advertising Age observed that, because it is relatively inexpensive to produce, the Leno show does not have to become a big hit. "It just has to beat its budget. Welcome to the future of broadcast." But the Hollywood Reporter wondered editorially, "If NBC winds up with significantly lower average ratings at 10 p.m. with "Leno" and 11 35 p.m. with "Tonight" under O'Brien, will anybody outside of NBC consider the maneuvering a success?"