Yeah, not comparable to Conan and Letterman where Conan signed a contract that basically kept him at NBC to take over late night, and Letterman was 11 and a half and replaced by someone with no real experience. Ferguson should have been consdiered and I'm sure he was but they chose Colbert. If they want to beat Fallon, you don't fight with Ferguson.
Ferguson has a stipulation/bonus in his contract that pays him more if he DOESN'T get the 11:30 slot.
Letterman hadn't beaten Leno in about 19 years consistently in the ratings. Don't know if Colbert is going to beat Fallon consistently for years. The Tonight Show, like Leno said, is an elite institution. Unless Leno himself took over Dave's spot, highly doubtful Colbert will steal Fallon's ratings.