I just got back from seeing the film. Truly monumental filmmaking and I think it's important to realize that Jackson had some crucial decision to make in bringing his version to the screen. The Arwen thread running through the first two parts covered a lot of material in the book about what was happening with the elves and their relationship with the world of men. Well, there's that word -- men.
Glorifindel was hardly a strong character in the narrative, so you ended up with only Galadriel in the first part and Eowyn in the second part. I think Jackson made the right decision for a film - bringing the female elf character out of the background in the appendices and using that character to tell part of the story. I don't want to get tied down to the "what would Tolkien think" school as he, after all, sold the rights to the book for a film many years ago. If alive, I would be happy if I were him that a movie maker like Jackson who obviously is in love with the material brought it to the screen with such effectiveness. He handled the multiple plots with an expertise I've never seen in any film -- it flowed like water (and plenty of water in that spectacular dam breaking sequence at the end!)
The Fanghorn forest is important in the film but I can see why the particular creatures that showed up in the book were left out. It didn't matter to me -- I liked the dramatic effect of having the Riders and Gandalf arrive at sunrise as promised and attacking from the rear when all seemed lost (even with the inevitable comparison to the calvary has arrived!) I would haved like to have seen perhaps more magical stuff going on, showing off Gandalf's new powers other than making the Riders virtually invincible. That was lost a bit in the shuffle but I'm going to have to see it again to absorb more of that aspect. This film is going to need that extra 30 minutes in an extended version more thant the first film even though it's quite satisfying as it is.
I wasn't as anxious to go back and see FOTR again as much as I'm anxious to see this film again. The scale is really pretty overwhelming.
It did elicit genuine emotion for the plight of the characters and I hate to focus now on one of my favorite parts of the films because it is that necessary bit of comic relief but the audience I was in laughed on cue. Gimli ending up behind a wall where he couldn't see a thing and saying, "You could have picked a better spot!"
Anyway, with the third part of the film, it will be the benchmark for any fantasy film to aspire to and likely any epic film. It had that feeling that this was actual history just like the book. I kept wondering where the elves ended up on this planet and what mythology picks up where LOTR leaves off.