I finally got around to seeing "X-Men: First Class" in the theater and was pleasantly surprised, given the only mildly positive reviews that I'd read. James McAvoy and Michael Fassbender were really good as Charles Xavier and Erik Lensherr (i.e., Professor X and Magneto), given that those characters were played by Patrick Stewart and Ian McKellen in the earlier "X-Men" film trilogy.
That said, I noticed a few continuity issues between "First Class" and its predecessors (SPOILERS ABOUND):
(1) Professor X and Mystique are childhood friends and even brother/foster sister? There's absolutely no sense of that prior relationship in the scenes between Patrick Stewart and Rebecca Romjin. You'd think something that major would have been mentioned at least. This is a clear retcon to emphasize the X/Magneto split on how best to deal with humans.
(2) At one point during the "recruitment" process, Xavier and Lensherr approach Logan (aka Wolverine, in an uncredited cameo by Hugh Jackman), who tells them to "f*** off." Very much in character, except that Professor X introduces himself, seemingly for the first time, to Wolverine during the first "X-Men" movie. Even if almost 40 years have passed by, it seems odd that the name wouldn't have triggered some memory. Now, I started to think that maybe this wasn't a retcon because at the end of "X-Men Origins: Wolverine," Logan gets shot in the head and loses his memory. But since Patrick Stewart makes an appearance in that movie and isn't paralyzed, the memory loss must have happened before "First Class."
(3) The U.S. and the Soviet Union learn about how devastatingly powerful mutants can be back in 1962, but it takes almost 40 years before some congressperson introduces mutant registration laws? That seems a little hard to believe.
Besides continuity, I had a few other questions:
(1) Why didn't Xavier release Sebastian Shaw when it became clear that Lensherr was going to kill Shaw? I suppose maybe because Shaw, once released, could again unleash his destructive power and start World War III. But wouldn't it have been worth it to bluff Lensherr with something along the lines of, "Erik, don't do this, I'm going to be forced to release Shaw"?
(2) Speaking of killing Shaw, would driving a coin straight through the middle of a person's brain kill him? I mean, I wouldn't want it done to me, and I'm sure it would mess things up, but it's essentially a low speed slice, so no hydrostatic shock or anything like that. It looked like it would sever the right and left halves of the brain, which I think people have survived. If you were going to kill the guy with a coin, shouldn't you send it facewise rather than sideways?
(3) Along those lines, why does the coin kill Shaw when bullets don't? What happened to Shaw's energy-absorbing power? Maybe it's active, not passive, so that he couldn't use it when paralyzed.
All in all, though, I really enjoyed "First Class" and look forward to the inevitable sequel.