With the recent admission by Hugh Jackman that he can't play Wolverine forever, we can safely say the same for Halle Berry as Storm (and more realistically of Patrick Stewart and Ian McKellen). Storm's death in the Days of Future Past comic is a poignant moment where in a last ditch effort, Storm and Colossus are killed while storming (no pun intended) the Baxter Building to destroy the Sentinels. While it might be hard to say if future Storm or present Storm would be the one to die, the nature of a time traveling adventure makes that easily reversed. The characters and fans alike would probably feel the impact of Storm's death deeply, and honestly it would be the most useful thing the character has ever done in an X-Men movie.