It may not be word-for-word, but it's still true to the original in ways many aren't even aware of

Rating: Null/10 (18 December 2002)

Spoiler Alert grrrr97, you've got to relax and take a step back.
Yes, there are some chapters missing from the end of TTT. If you paid attention during the film, you'll remember Gollum deciding to let "her" kill the Hobbits. "Her" is obviously Shelob, so it becomes apparent that PJ is merely finishing off here, for now... and we'll see the rest in the next film.
Remember that The Return of the King is much, much shorter than the first two parts of LOTR. So, in the interests of turning a profit, New Line and PJ are making three, 3-hour films... instead of a 3-hour film, a 4-hour film and a 90 minute film. Most of Return of the King is battles. This way, we'll have a great setup, then great battles.
As for the Arwen-Aragorn storyline. These are excerpts from the appendix that Tolkien himself wrote detailing their long courtship. It serves three purposes here: 1) to give us an idea of what the issues are vis-a-vis elves and men; 2) to give the less-than-pedantic-Tolkien-fan public something akin to a love story (I don't know if you've noticed, but there is a lot of epic-fighting and very little else going on) and 3) graft in a beautiful story that many people aren't even aware of because they got to the end of ROTK and saw a couple hundred pages of what they assumed to be family trees and glossaries.
Reading LOTR again has given me an appreciation for how much narration Tolkien did. For all the story and pagecount, there isn't that much dialog between characters. In a visual medium like film, you can't relate the fact that beyond Middle Earth elves and men are doomed to be apart till the end of time unless somebody speaks it. You need to fill people in if they haven't read the books.
You or I can cry bloody murder all we want, but at the end of the day, PJ has done an outstanding job of staying true to the original story while making a film that EVERYONE (not just the Tolkien geeks) can enjoy.
There's a lot more in adapting a masterpiece to film than just reading the original manuscript.