"The Return Of The King is quite close to the book. There are notable exceptions. The first thing with the Return of the King is that we still have to wrap up The Two Towers. We have the Isengard sequence in -in which they go to Isengard to deal with Saruman who is imprisoned at the top of a tower -which is at the tail end of the Two Towers book. It is now at the beginning of the Return of the King movie.
Likewise, we don't have the scouring of the Shire, which is a major chapter at the end of the book. I have always found that sort of anti-climactic...It felt wrong when I read it, so we definitely don't have that in the film. When the Ring is destroyed at the ring at the end of the Return of the King, that is the real climax of the film.
Those two are the notable major expections as well as Shelob, which is another spill-over from The Two Towers-Minas Morgul, the stairs of Cirith Ungol and into Shelob's tunnel are now in Return of the King. When fans of the book see that sequence, I think they will understand immeadiately how impossible it would have been for it to have been it in The Two Towers film. It feels so right to be where we've got it from a story point of view -for reasons I can't discuss now!
At this point, we don't have Ghan-buri-Ghan...I don't know if this will change with us doing pick-ups, but I doubt it.
Having said that, the rest of the Return of the King movie is going to follow the book reasonably well. What I like about the Return of the King is that the story is the centerpiece of the film, more so than in the first two films...It has a story that unfolds in a very exciting way. I think that is going to make it a very strong film, because you know the places, you know the characters and you know the situation. We only meet one new character, which is Denethor- and he's only new if you don't check out The Two Towers extended cut in November! We're now just simply paying it all off withn a narrative that twists and turns and unfolds in quite a thrilling way."
That's pretty much all the interesting stuff regarding RotK. There's a lot more in the interview, but it's pretty general stuff about the film making and editing process, not worth transcribing.
Spoiler alert! See above.