It's hard to picture exactly where they would go from here without having first seen the actual film, but doesn't it seem like Kraven's persona is ripe for reinvention and could work very well in (what we've seen of) the Marc Webb Spider-Man universe? Electro, meanwhile, is a character whose visual only really works in comics and animation and would have to be reinvented from the ground up to work in live-action film. It might be problematic for a film that seems to be trying somewhat to stick with the source material.
Certainly you'd want to distance yourself from Green Goblin and Dr. Octopus--even Garfield associates them as much with the Sam Raimi movies as with the comics.
"I think I like Doc Ock especially because of what Alfred Molina did," the actor told MTV News of the actor who played Doc Ock in Raimi's Spider-Man 2. "He made that so memorable and kind of profound, somehow."
The Amazing Spider-Man opens in theaters in the U.S. on July 3.