I'm an old school X-Men comic reader. For those who don't know, someone said it before, I'll say it again, check out the dark phoneix saga.
The whole thing will play out quite interesting because as I remember, Jean Grey as Dark Phoneix was quite a bad girl. She was a mass murderer and began by destroying many of the X-Men's enemies with her mass powers including the Hellfire Club. She then lost her mind and went on to battle her former friends until she was finally destroyed. I hope we can see Jean Grey turn bad ass in the third installment.
The interesting thing is, when the comics were being written, and the writer (I forget if it was Chris Claremont at the time or not) wrote the scene where she killed over a million people, the editors of a then very strict Marvel, told the writer he would HAVE to kill Jean Grey because of what she had done. The writer then had plans for Phoenix but ultimately had to write her death under the strict guidelines of Marvel's law of mass murderering villians. It ended up being the most classic storyline in X-Men history.
In X-Men 3, yes I'd like to see Gambit and many others, but I really really want to see Havok, Cyclops' younger brother. That would be great.
Great movie. I've seen it twice so far. I loved Pyro and I can't wait to see him and the Brotherhood tearing up the streets.