Yeah, STAS Luthor was black... I didn't notice it when I was a kid, but looking at it in retrospect, it's pretty clear what they were trying to do.
I hope Luthor is as compelling as the Joker. As completely rational, but ultimately and spiritually wrong, in his logic and outlook, and completely brilliant in the way he manipulates everyone and everything against Superman. Any machinations of using some sort of powered armor to take him down would be a ruse. I'd love to see a different Kryptonite color other than green involved, and really take it to Clark Kent on a personal level, wooing Lois, buying up the Planet, etc, etc. Trying to prove that Clark isn't good, isn't human and isn't capable of protecting/saving the planet.
He should be smooth as butter, basically a Bruce Wayne type. In fact, a bald Bruce Wayne is probably a good tack to take. The movie should really answer the Superman vs Batman question without Batman ever showing up.