They better bring in Lex Luthor. Seriously. He'd be a perfect villain for this.
Wouldn't that be too much? You have to fit the whole Superman/Batman introduction and then interaction alongside a massive villain. It would probably mean at least one half of the film would feel a bit rushed - you only really get one chance to do a Lex Luthor film, and one chance to do a Bat/Super intro.
A dark and gritty Batman but not quite as realistic as Nolan's I'd guess.
Yeah, maybe a similar style to Gotham and the villains, but a bit more 'charisma' (not sure that is the best word) to Batman?