For me, I would have to say that, you finally see a different side to Edward. One of pain, and torment. He is so used to handling everything and if he can't his family will help me. But they become divided. He thought of himself as Bella's protector. And when she became pregnaunt, he thought of himself as her murderer.
I think that's a great observation. It's also the first time Edward has been forced to accept that he may be powerless to save her despite all his previous efforts, and also has to deal with the fact that Bella has her own mind. The earlier times that Bella stood up to him--with Jacob, for instance--were about her making her own choices and following her heart even if Edward didn't like it. He was willing to admit she had that right. In this movie (and book) her choice is one that she's really making for both of them. It's the first time that she's really imposed her will on Edward in a way that really has meaning and impacts on their relationship. Add to this Edward's guilt over the pregnancy and it's no wonder he's acting out of character!
I've always like Rob as Edward, but certain scenes in this movie--like when he confronts Bella--really showed such a wider range than anything he'd done in the role prior, in my opinion. It's almost as though Edward is forced to grow and change and Rob's acting follows suit, if that makes sense? He's been freed up as an actor by the change in Bella and Edward's dynamics.
Yes Shannon I agree. What we saw of him in the movie, is exactly what we needed to see. He proved he had emotions. All the other movies he seemed just angry all the time, but with this one, we see his hurt and pain and the depth of his love for Bella.