One, the movies are NEVER as good as the books. Movies are one dimensional. You can't get inside a character's head like you can in a book.
Second, I hate having a visual thing for stories because it changes the way characters looked to me. Know what I mean? I used to picture Tris a certain way and now when I reread Divergent I see Shailene Woodley. When I reread Hunger Games I see Jennifer Lawrence. I like the secret place in our heads where characters are unique to each of us. Movies make them universal, and that bugs me.
But, those thoughts aside, I am ridiculously excited about this:
Just the trailer turns me into a hot mess of tears.
If you haven't read The Fault in Our Stars, you need to. Such a great story.