Bryan Singer recently answered several questions for fans via this Facebook Q&A session that occurred and one of the fun little facts to come out of it was that he really wanted Quicksilver to be in the movie, though he didn’t elaborate on it more than that. When asked what power he’d want the most, he went down the path of teleportation ala Nightcrawler and expressed that Professor X is his favorite mutant. One area he did touch upon is why the movie doesn’t follow the original comics to some degree with its origins, stating:
“I felt that to earn the ‘First Class’ title, it was important to go back to the formation of the X-Men and the beginnings of Xavier and Magneto’s relationship.” In addition, he went on to note that the 60’s was ideal for this kind of origin movie as, “It is a time of socio-political upheaval in the world. The height of the cold war period. The birth of the civil rights movement,” he explained. “And the birth time of the X-Men comic book.
