You say you're a fan of the XMen comicsm but you'd never heard of Magneto before?
Please say you're kidding! He's only been the most reoccuring Bad Guy in the comics!
Then there was the time he was a good guy, and then he was bad again, then he was good, then he was bad....he's been dead a couple of times, regressed to a baby once, cloned at least once....
He and Rogue sure hit it off in a couple of sequences!
Plus he's Quicksilver and the Scarlet Witch's father....
He's...wow. Magneto and the XMen are almost synonymous. And I fully expect him to show up in future sequels to the movie!