Dave on Demand: Who needs Charlie?

As Charlie Sheen's bareback rodeo rolls on, the consensus seems to be that if Charlie goes down, so does the show, that Two and a Half Men simply cannot survive without him.

Balderdash! (Or was that Fred Flintstone's boss?) If TV has taught us anything, it's that everyone is expendable.

They body-swapped Roseanne's daughter, Blake Carrington's son, Samantha's bewitched and bewildered husband, the Fresh Prince's aunt, even Ralph Kramden's wife.

From William Petersen to Bob Barker, George Clooney to Simon Cowell, series have often lost their stars and still somehow forged ahead. Dunder Mifflin will remain open for business after Steve Carell retires in a few months.

It may not be the same program. It may not be as good. But the show will go on.

A gun-shy Conan O'Brien joked that he had named his new TBS talker Conan so that he would be harder to replace.

But even having your name in the title doesn't make you indispensable. Just ask Larry King. Or Valerie Harper. When she quit Valerie, NBC brought in Sandy Duncan to replace her and rebranded the sitcom The Hogan Family.

Finding a fill-in for Sheen really isn't that complicated. You just need an actor who can carry off a roguish air of dissolution.

Kiefer Sutherland, David Boreanaz, John Stamos, Antonio Sabato, Josh Holloway, and half a dozen others could pull the Two and a Half Men plow tomorrow without breaking a sweat. If you got really desperate, you could probably scratch out another season with David Spade as the sitcom's bad boy.

The last time there was this much talk about a star's departure's dooming a show was when Michael J. Fox bolted Spin City. ABC immediately plugged in a serviceable substitute: an actor named Charlie Sheen.

Inescapable. Justin Bieber isn't a singer. He's a self-promoting tsunami.

The teenybopper has been everywhere this month. From Live With Regis and What's-Her-Face to Late Show With David Letterman. From Today to The Daily Show. From Chelsea Lately to the Grammys. He was even (I'm not making this up) on CSI and Extreme Makeover: Home Edition. I wouldn't be surprised if he made an appearance on Sabado Gigante.

Even when he wasn't there, he was there. Glee turned into a virtual tribute to Bieber this week. At one point Puck meekly admitted, "We underestimated the power of the Biebs." We all did, buddy.

What's the deal? Can someone tell me what criteria the new panel of American Idol judges is using? Because it sure isn't merit.

Time after time in this week's group round, they advanced singers who badly butchered songs. Chris Medina, Brett Loewenstern, John Wayne Schulz, and Ashley Sullivan all gave performances that were, in J.Lo's pet phrase, "almost painful." Singers were even graduated who committed what Randy Jackson has lectured them repeatedly is the one unforgivable sin: forgetting the lyrics.

If American Idol has become a producer-rigged popularity contest, please let us know now.

Too close. This week's episode of NCIS began with a disturbing bit of verisimilitude. A suicide bomber targets a ceremony attended by the U.S. secretary of state. The show intentionally used a Hillary Rodham Clinton look-alike right, down to the pantsuit and Flock of Seagulls hairdo.

Was that really necessary? Would the plot have been altered in any way if the secretary had been played by a random actor?

Unreasonable demands. The most savory line of the week came on Mr. Sunshine. Guest star Nick Jonas played a spoiled singer on tour. But instead of Cristal champagne or brown M&Ms in his dressing room, he demanded a DVD of the first season of Brothers & Sisters. And tout de suite.

That led to arena manager Matthew Perry disgustedly slinging a hastily secured disc at Jonas and saying: "Twenty-two hours of Sally Field. Lose yourself."