See, my feelings are kind of the opposite: despite Elmo's constant state of happiness and such, his personality is such that he can kind of adapt to almost any kind of situation, scenario, or setting, while still remaining in-character and endearing as always . . . he can feel "real" with people. As much as I love Cookie Monster, Oscar, and Grover, they don't quite have the layered personalities to really pull off something like this, IMO . . . I suppose Oscar could be an even grouchier version of Letterman when he was younger, but Cookie Monster (especially David Rudman's more childlike Cookie Monster) doesn't quite have the engaging people skills, and as much as Grover has been arguably Flanderized in recent years, I can't see any talk show he attempts to host not end up a disasterous trainwreck . . . it might make for an amusing one-shot special (a la THE FANTASTIC MISS PIGGY SHOW), but the schtick would get really old, really fast for an episodic series.