Jesse Eisenberg...there's nothing sinister about him. He doesn't have the greed or malevolence in his performances thus far that is intrinsically wrapped up in Lex Luthor's character. Even his arrogant roles aren't really the kind of arrogance Lex displays which is based on a superiority complex of his intellect and high standing place in society. I just don't see him as Lex Luthor in the slightest and this is another fatal casting error that could go drastically wrong. Eisenberg just doesn't have the acting chops to play Lex Luthor IMO.
@jedixman: Oh gotcha. I agree, they are all great castings, but for Black Adam for example, I tried to make it look like The Rock, but more Egyptian and menacing. And Ian McKellan was a great choice for Magneto, I just wanted to make him look more like how he does in the comics.