The New York Times posted this great look at where each clip of a trailer comes from. The interactive graphic shows that most trailers do follow the general chronological order of the finished film, with some obvious ommisions so as not to spoil the movie.
It's also fun to see just how quick the clips are depending on the genre of the movie. For Argo: "[The trailer] balances two different tones, according to Mr. Garrett: thriller and Hollywood satire. 'Thrillers have a very fast cutting style,' he said. 'It’s a way of ratcheting up attention.' Shots are longer, on average, when the trailer turns to satire."