If they don't put a super powered baddie in this film there might not be a sequel

One of the biggest complaints about SR was no genuine super villain. We've seen lex to death. Spidey, Iron Man, Hulk, they all got villains that could challenge them on a physical level. It not only makes for a good movie but adds a nice visual layer to the film, like for me, the fights in Spidey 2 are the closest thing i've ever seen to a comic book coming to life on the big screen. People get bored really easily, they've seen superman stop a disaster and lift an island in the last film and battle lex. I we'd all be epically disappointed if we didn't get a solid superpowered villain this time around. Even smallville tries to give him worthy threats.
With a movie for the first time ever we could actually see superman doing things he's only done in the comics and cartoons up til now, having an amazing battle against a formidble foe. Whether it's a giant robot, human size bots, or a hulk like beast, seeing superman tangle with those sorts of threats would be amazing. People like and expect spectable in this type of movie. Look at Avatar, it was visually amazing, people want to get caught up in the fantasy of it. They need to get superman right this time. Fun + exciting adventure + epic battles = a winning combo. If they go with no supervillain, more lex as prime villian, supes stopping disaster, it will equal epic failure. And no one wants that.