Man, I can't remember the last time I saw a movie tank in the third act as suddenly and as completely as Spider-man 3. Everything was running along pretty smoothly for about 1 1/2 hours -- no easy task when you're juggling that many characters and subplots -- and then out of nowhere, BOOM! Trainwreck! It's like they had a million neat ideas and no plan for how to tie them together and wrap them up. Unfortunately the method they seem to eventually have settled on was "horribly contrived and ridiculously out-of-character cheesy left-field B-movie style."
Man, I know there were a lot of things I really liked about the earlier parts of the film, but the ending was so awful that I'm having trouble remembering what they all were. Meanwhile, it felt like a lot of the story was just... missing. Inevitable extended DVD edition? My money is on "yes."