I got a copy of the original Frost/Nixon interviews, on which the current film is based, free with the paper last Sunday... still need to watch them, though. Especially since its apparently the closest anyone got him to make to an apology for Watergate.
The current film, while interesting, is carefully edited and omits the background.
In reality Nixon was making a six hundred grand off the interviews, and knew he had to say something to get high ratings. Even then, he was his usual self. In fact people watching the interviews at the time considered it pretty bad.
See Elizabeth Drew for more.