Obama's barely been president elect for 5 minutes and South Park have already done an episode about the election aftermath. Worth watching if you like that sort of thing, and even if you don't you have to admire how fast Matt and Trey can write and produce a finished 25 minute cartoon!
I watched it last night and was just laughing. It was a good episode.
More than likely they had a lay out ready for both outcomes and the starting bits would have been done on the fly. I had a friend who used to write for them and that is how they would do certain episodes for important events.
that was pretty good - it looked like they did do a fair bit in the few hours they had though. I wonder how much cocaine, sorry Red Bull, was consumed in the process?