Gotta agree with you on this. I specifically noted Aragorn. Although I think PJ cheated a little on this. In the book Aragorn is not nearly as self-doubting and retiring in the beginning as he is in the movie. After all, he is like 80 and has held high military office under both Rohan and Gondor, and probably other countries, too.
This initial diffidence allows PJ to maximize the change in his character as the movie progresses.
My thought as I watched the preview was that Aragorn was going from being Rambo to being Patton!
To me, he doesn't get it together until the night he spent wrestling with Sauron in the palantir. When he comes out from doing that... he is changed. And everything he does and says is decisive and kingly.
In the movie though, you don't get any of the indecision. (Except a little bit in Rivendell) He takes control of the group right after Gandalf falls.
I don't mind the movie Aragorn at all. In fact, it wasn't until I saw the movie that I began to have appreciation for the character.
Anyway, let me know what you think.