Re: Who should be the villain in the sequel for Man of Steel?
The good thing about a Bizarro is that you don't need to build up the character really, so that we can have more with Lex, Bats, Lois, etc. You can also have plots about framing, control, power, etc.
The problem with Metallo I think is that you have to develop Corben's character. At that point, why not just put Lex in the suit.