Random thoughts, in no particular order:

The late night segment in the U.S. used to be very simple: Johnny Carson followed by David Letterman. When I was in junior high and high school, I taped Letterman and watched him the next day after school.

Also, keep in mind that the U.S. is four timezones. In US-Central, we see shows the same time as US-Eastern, which is to say, a show scheduled at 11:30pm Eastern shows at 10:30pm Central. Seems much more civilized. They then tape delay things for US-Mountain and US-Pacific.

The modern proliferation of cable TV has really messed things up. I watch Jon Stewart and Stephen Colbert (10pm-11pm US-Central). There's only one Comedy Central, nationwide, so west coast people could watch Stewart at 8pm their time. Stewart and Colbert are repeated again three hours later, or something like that, so west coast people can also watch them in the evening timeslot. Yes it's confusing.

Speaking of proliferation, we now also have Jimmy Kimmel on ABC. As such, the evening talk-show slot has become quite crowded. I'd say it's very much up in the air how this is all going to shake out. If NBC buys out Conan and he ends up on Fox, we'll then have five major evening talk shows duking it out (the four networks plus Comedy Central). It's deeply unclear the market is big enough to support all of that. My money says that Conan doesn't go late night but instead ends up somewhere completely different.

Who knows, maybe he decides to build a SNL (or Python)-esque sketch comedy show.