There are NO Supervillains in Superman Returns. This is back to basics (in a manner of speaking) with just Superman v. Lex Luthor.

As of yet there is no confirmation or even rumor of Lex's battle suit from the comics. It's highly unlikely we'll see it. Also, the film's tone isn't one of bashing each other around the city, so it's likely we'll see more psychological warfare between Lex and Superman.

However, Signer himself said at Comic-Con that there will be plenty of action.