To judge by the slobbering devotion displayed by most daily newspapers these days, you’d think that The Sopranos was more or less the only program left on television. (Okay, they also admit to the existence of Desperate Housewives.) And certainly, the New Jersey mob drama has built up quite the following over its five seasons. So it had to come as a shock to HBO (and all those adoring critics) when the premiere episode of the show’s final season lost fully 1/4 of its audience from last season.