With the Wolverine movie coming tentatively this summer, and X-Men Origins (formerly Magneto) sometime after that, I'd say it's definitely possible for Hasbro to try to cash in on it with a line of "X-Men Classics" type figures. My wish list in order...
Magneto's right hand man, Pyro is a MUST.
She's the only member of the X-Team without any action figure, pretty self explanatory.
He may not have had a big part in X3, but the Brotherhood needs to even the odds against all those X-Men, and Madrox can do it single handedly! Great army builder potential.
He may have never actually joined the X-Team, but that doesn't mean he never will. The prototype was looking pretty sweet, I say make it.
We got a few Rogue figures in the X1 line, one of them being a battlesuit Rogue, but the thing was so out of scale it's in no way an acceptable substitute. The cure looks like it may not be as permanent as it seemed, so give Rogue a proper figure in her uniform!
Iceman got a nice figure in the X2 line, the problem is his uniform wasn't ever used for anything other than promotional photos. Give Bobby his proper uniform so he can match his team, and make an icy variation while you're at it.
I've always found the Storm figure from X1 to be good enough since her uniform didn't change in either of the sequels. I'm not a big fan of the pre-posed nature of the figure and limited articulation though (not to mention the hair), so Storm is definitely in need of a new figure.
The first Wolverine figure from X2 was missing his belt buckle, had a giraffe neck, and the likeness left a little to be desired. The second series version fixed all those problems, but the figure also gained an action figure and lost a good amount of articulation. We really need a Wolverine that has the best of both worlds, he's only the main character in the films after all. He needs a worthy action figure.
Mystique (Super Articulated)
Mystique has looked the same in all three movies, but her articulation in her X1 figure leaves a lot to be desired. Considering how acrobatic she is, Mystique could definitely use the super articulated treatment.
Sabretooth (Super Articulated)
Sabes got a few versions in X1, but it'd be nice to have him with more articulation and less action features. And with his rumored role in the Wolverine prequel, I’d say a new Sabretooth figure is extremely likely.
Didn’t stick around long enough to get one in the films, but if Angel can get a hypothetical X-Suit, why not Kurt?