I've seen X2 twice now, and both times, it was exactly what I was hoping it would be.  Since this is a spoiler-free review, I'll just gloss over the story.  Tensions between the mutant and human populations have risen following an incident involving a mutant and the President.  The President gives authorization to William Stryker, who has convinced him that the X Mansion is a training ground for mutants, to infiltrate and detain any mutants found at the premises.  Meanwhile, Wolverine is still searching through the snowy wilderness for traces of his past.

If you're going to see X2 and you want to understand all the subtleties, you really need to have X-Men fresh in your mind.  There are several references that I really liked to events from the first film.  Not only that, but, almost like The Two Towers, there is little to no catch-up here.  Bryan Singer (director) expects you to know these characters and the world in which they live.  I think the best way to get through my thoughts on the movie is to go through the mutants that make appearances.

NIGHTCRAWLER - Alan Cumming

What can I say?  He is the character I always wanted to be on the playground as a kid, so seeing Nightcrawler in action was fantastic.  Nightcrawler's introduction is the reason I go to comic book movies; to see those moments that were so cool as still images on a page brought to life with live action.  I knew that Alan Cumming would be good as Nightcrawler when I read he was cast.  He captures the piety, fear, and isolation perfectly.  I understand that Alan is signed for a third film.  The teleporting effects are perfect and, although it doesn't sound like BAMF, the sound he does make is cool.

WOLVERINE - Hugh Jackman

When I first saw a picture of Hugh Jackman with the caption "cast as Wolverine" for X-Men, I was unhappy.  I wanted a big name actor so that Wolverine would be the focus of the movie.  However, I turned into an instant Hugh Jackman fan the first time Wolverine shows up in the first film.  He was the character in my eyes.  Fanboys will say he's too tall and too skinny and not hairy enough, but I think if he were 5' 6" instead of 6' 2" he would not have the screen impact.  For movies, taller is usually better (see Hulk starring a 15' rendition of the character).  My only problem with Wolverine in the first film was that he didn't really do the berserker rage.  He had some good moments, but he never really cut loose.  This has been remedied in X2.  Wolverine hurts people...many people...a lot.  His past is developed a little in X2, but maybe not to the point that the audience would like.  He is still a mystery.  The shots of him coming out of the facility covered in blood are straight out of Weapon X...good stuff.

CYCLOPS - James Marsden

I hear complaints about this kid, but I really liked his performance in the first film.  He's kind of brushed aside this time, which I think is too bad.  Cyclops was the unofficial leader in the first film, and he doesn't really get have that responsibility in X2.  He only gets a couple of very brief optic blasts, and is missing for a good portion of the movie.  I hope that they bring in his brother Havok for the third movie and develop him a little better.

STORM - Halle Berry

I was never a big Storm fan, and I'm still not.  I think she would be a cooler movie character if they went in to her past where she was worshipped as a goddess in some remote island.  I believe that her part was rewritten after Halle Berry won the Oscar, which is fine, because she does a great job in the role, but compared to the other characters, she just isn't that cool in my opinion.  The X-Plane escape is pretty cool, but outside of that, she just is.

ROGUE - Anna Paquin

This character does not resemble the character I liked from the comics.  Rogue wasn't truly cool for me until she absorbed the powers of Marvel Girl (I think) and became Hulkish strong and could fly.  I believe she was also kind of indestructable and drop-dead sexy (see the X-Men cartoon from 92 to 97).  In the first movie, Rogue was the damsel in distress.  In X2, we see a more confident and comfortable Rogue, and her romantic subplot with Iceman is mildly interesting.

JEAN GREY - Famke Janssen

Maybe I just have problems with the female X-Men, or maybe it is that their powers don't make for good special effects.  I really like Famke Janssen, and I really really like what they do with Jean Grey in this movie because it suggests very big events in the coming movie, but I don't get excited about her being on screen.  They play on the sexual tension between her and Wolverine, and that stuff is good, but I don't think she'll really shine until the next movie.

PROFESSOR X - Patrick Stewart

I'm still extremely happy that this casting choice happened.  Rarely, does the casting go the way that ALL the fans want it to go, but in this case it did.  Xavier's role in X2 is different than his role in the first film because we become aware how powerful he really is.  His scenes with Magneto are just great to watch because these two guys know how to act.  Xavier's idealism is still a hard sell to me, and I almost find myself siding with Magneto when I put myself in his shoes.

MAGNETO - Ian McKellen

Here is a casting choice I thought was WAY off at first, but I loved this character from the first film.  Magneto is not the villain this time around, but he is still villainous.  He is also lots of fun to watch.  Ian McKellen makes Magneto dangerous and charismatic, but also sells his motivation.  Magneto doesn't think he is the villain.  There is a great scene between him and Pyro in the X Plane that I really liked, and the interaction with Mystique is very good.  There is no sexual tension between them, they are just partners.  When Magneto and Mystique find themselves teamed up with the X-Men, it's great stuff.

MYSTIQUE - Rebecca Romijn-Stamos 

Even though she is a big departure from her comic book counterpart, I liked Mystique from the first movie.  In X2, she is even better.  Even though she never gets much dialogue, the lines she does get impact well.  She gets more screen time in this film, and really takes advantage of it.  Once again, knowing X-Men will help here, especially concerning her interaction with Wolverine.  Rebecca Romijn-Stamos just sells her contempt for people very well.

ICEMAN - Shawn Ashmore

Bobby Drake is skewed younger in the films, so he is considered one of the budding X-Men.  His romance with Rogue is interesting, but he seems to have a pretty good handle on his powers already.  I would like it if the kids were practically out of control when they started using their powers.  They all seem pretty adept with them.  He shows some promise for later films, but doesn't really have much to do here.

PYRO - Aaron Stanford

I liked how they handled Pyro.  In the comic book, he is part of the Brotherhood of Evil Mutants, but he starts as one of Xavier's kids here.  You see his frustration during the movie, and Magneto preys on it.  Like I said earlier, I really like the scene they have in the X Plane.  Pyro could also be a really cool developing character.  There is a scene where he is looking at pictures of Bobby Drake's family with what looks like envy, but it hard to tell.  I would have liked some explanation and some backstory to him.  He is young, but he seems to have already tried to deal with the mutant/human issue.

DEATHSTRYKE - Kelly Hu

This is a cool role, but just not enough.  She is basically just in the movie to fight Wolverine.  Their fight is good, but it would have been nice to get to know this character a little first.  There just isn't much there.

CAMEOS

Some other mutants you'll see scattered here and there in the film are Colossus, Siryn, Shadowcat (Kitty Pryde), Beast (although not wearing blue fur), Jubilee (ugh), and if you watch carefully you'll spot Gambit's name (Remy Le Beau) in a list of mutants.  By far, Colossus was the favorite.  Both times I saw it, his small scene gets applause. 

So there you have it.  Some things I'd like to see in the next movie are Gambit, Juggernaut, the return of Sabertooth, Angel, and more of Colossus.  I wouldn't mind if they went in the Sentinels direction, although it might be hard to see giant mutant hunting robots.  I definitely want to see more mutant vs mutant fighting in the next film, and not just one one one.  I want two teams of mutants fighting and causing the destruction of a city or something.  I want an epic shot from high above the city of 10 mutants all fighting each other.