I'm almost to the end of my current interest in this topic but…
Friday night, Jay Leno led the three network late night shows by a handy margin in both total viewers and the coveted 18-49 bracket. When all the numbers are in, it'll probably show that Jay won the week and also won the total of the four days when Jimmy Kimmel's new show was directly opposite The Tonight Show and The Late Show. Kimmel will be in second place. Letterman will be in third.
Now, that's just the first week of this three-way contest but if Jay can keep doing it…well, the argument among those at NBC who advocate dumping him and bringing in a younger man is that the younger man will do better in 18-49. It will be hard for that argument to prevail if Jay continues to beat a younger man in that demo. Kimmel's career in TV (on his current program and also on The Man Show over on Comedy Central) was always about how well he delivered young male viewers in the 18-49 category. I'd be curious to know if the reason Jay's doing better with younger viewers is a gender-gap thing; i.e., Kimmel's snagging males and the females are going to Leno. I rarely hear anyone who doesn't care for Kimmel not use the term, "frat boy humor."
In the meantime, if you think Letterman's been ornery since he started finishing second to Leno, wait and see how he is if he trails Kimmel for a few more weeks.
Getting back to Jay: As you may recall, the rumor was around recently that NBC had decided to retire Jay and move Jimmy Fallon to 11:35. That rumor apparently was premature (at least) and a lot of folks think it'll never happen; that even if Jay got run over by one of his eighty thousand cars tomorrow, Fallon would not automatically ascend to the earlier slot. There seems to be a belief out there that there's this grand tradition and understanding that 12:35 is a training ground and that if you succeed there, they move you up.
In the history of late night talk shows, this has happened exactly once…twice if you count ABC flipping the times of Jimmy Kimmel Live and Nightline. Conan O'Brien was moved up because he was threatening to go elsewhere and compete, and NBC didn't want to lose him and thought Jay wouldn't be able to sustain the numbers he'd been doing. As we all know, that didn't work out as planned.
The problem with dropping Leno and moving Fallon up is that NBC creates two uncertainties for themselves at the same time: Will Fallon's act play as well in the earlier slot? And who do you get to replace him who'll do as well at 12:35? I am told by someone involved in the late night game that many of the NBC affiliates have told the parent network, in effect, "If you replace Leno, you'd damn well better have someone phenomenal to take over that time slot." That doesn't mean the programming guys might not come up with someone they think would be phenomenal…but I don't think they're in a rush to risk having both 11:35 and 12:35 collapse at the same time under new management. Not while both shows are winning their slots in both total viewers and younger ones.