I've put this off long enough. The movie was crap. Almost everyone died and I'm not even sure what the storyline was suppose to be. There were at least three of them. That said, I would say it's just barely worth watching. Certainly not something I'd want to watch twice.
The whole film was basically a moral quandary for Peter on whether or not he should date what's-her-name because in the last movie the girls father's dying wish was for Peter to stay away. Naturally, Peter felt guilty about this and it ends badly. I was near tears.
Now, the commercials lead you to believe that the movie involves some blue guy as the main protagonist but really that guy was hardly around. I mean literally, he's only reason for fighting is because "nobody sees me". Finally, Harry Osbourne has some hereditary disease that his dying father just told him about and suddenly he acts like he's got days left and things happen. I won't say too much about that but he does end up a crazed evil mastermind.
All in all, I think the creators just tried too hard. They should have focused more on blue sparks with hints of love problems then adding all the other characters they did. The green goblin should have been left for Spider-Man 3.
One last peeve! The constant whistling and theme song ringtones were completely unnecessary. I mean, once or twice would have been great but they were constant.