I'll watch the film, but like the Harry Potter films I'll probably just end up being annoyed by the changes in storyline. I can understand when they cut things out for time or whatever, but why do they change the actual storyline sometimes? If a book's good enough to be made into a film then there should be no need to change the story.
Hopefully it'll stay true to the books though... I still haven't read the third one actually, might try and pick that up somewhere.