I just had a thought. I think it's very likely that Norman Osborn will become Green Goblin in ASM2 and kill Gwen at the end. That means he'd have a huge role in the last parts of the film. I think Sony wouldn't want to have Green Goblin as the only villain in ASM3 if he already has his greatest scenes in ASM2. I think Green Goblin will be this villain that will have the largest role of the trilogy, yet still be "in between" other villains. I think it would be extremely cool to have Mysterio have a big role in ASM3 after Gwen's death. He could be used by Green Goblin to **** up Spidey's mind completely, just to have Green Goblin take advantage of that later on. That way we'd know that Green Goblin would be a villain in ASM3 yet still have something new and exciting to look forward to.