Man, things are not going well for NBC. The Tonight Show has had the highest ratings among 18-49 year olds for seventeen YEARS - until now. CBS’s Late Show with David Letterman took over the top spot during the just-finished November sweeps rating period. More people overall are still watching Leno, but luckily for Letterman, the key demos count for a lot. Look out, NBC. CBS isn’t just for old people laughing at Charlie Sheen’s sexploits anymore!