Jubilee made cameos in the two movies previous to this one as well.
The problems with having a series like X-Men on the movies, is that you have up to 2 and a half hours to show off what you think the best plot storyline is.
I think they should have just got a contract with fox and make it a Live action show, kind of like smallville, but more set in the better part of the series, not showing teens revealing their powers and what not. But the trade off of doing this would be to lose your major actors, your Halle Berry and your Hugh Jackman, Captain Picard might stay seeing as how he was made famous through television. Through a series, you can expand relationships, and develop charcters as well as adding characters and developing plot lines.
Well thats my two cents upon that scenario.
[/May CONTAIN SPOILERS]
On the subject of the whole lets kill of some dire characters, I mean I guess the director could do that, though Stan Lee usually sits in on most marvel movies to review the storyline and gives his suggestions and what not. In the second movie they introduced that Pshycic kid that was completely made up, along with the story line of Wolverine's origin and the side stories of Pyro joining the brotherhood and Lady Deathstrike dying, the movie wasn't that bad. Let's not forget that Lady Deathstrike isn't supposed to die(?)
However this storyline could be the one that is played out in Bishops timeline, where the X-Men died and the sentinel program is an active mutant killing program, and the X.S.E go and try and save them in the past with little fillers of the Cable tragedy occuring. But that's one thing about the marvel universe, time travel is possible. Just like in AoA when everyone was killed off/close to dead they just had Bishop go back, and wa pow, that timeline never happened and all of our faves that died were brought back or faves that never lived were brought to life again.
edit: On the subject of the all powerfull mutant, are you guys talking about the mutant that has the power to "cure" other mutants. (BTW i think this is the crappiest idea ever.)