I agree that this movie had too much going on in it. There were too many big storylines thrown in for a movie so short. After going to see it ages ago, I immediately thought the movie could have done with at least an extra thirty minutes thrown in, but even then I think it would have been a struggle to do the film's storylines justice.
One of the main problems I had with the movie was that it was just overloaded with the minor characters, that took away from the focus a lot of the time, and at the same time frustrated me because it really compromised a lot of characters such as Psylocke and the rest. Characters like that really deserved a bit more screen time and focus, and they just threw away so much potential in favour of quick cameos.
The killing off of several major characters didn't help either. Like I said, in a movie so short with so many underdeveloped ideas, it's a bit of a big leap to off so many key players. If the movie had have been a bit longer, I could have accepted Xavier's death in addition to Jean's, but the addition of Cyclops thrown into the there just took away from the whole thing. He'd never been used to his full potential in the movies, and it just seemed like an even bigger offence at the character that he was seemingly just killed off so that the bigger stars of the movie (namely Halley Berry and Hugh Jackman) could edge even more into focus. I don't have a problem against that really (I really loved how Storm was finally given a lot of action sequences) but there was also a lot of really weak dialogue put in there, that was just unecessary. I know that seemingly goes against my complaint the movie was too short, but the point is there was too much focus on a few characters, padded out with a lot of thin dialogue, and barely any attention paid to the other characters, many of which are franchise regulars.
It's a bit of a disgrace to the excellent X2 to be honest, and this film series most definately neeRAB a fantastic forth installment to make up for the third movie.