- Gwen Stacy's death. This should come at the climax of the second movie and propel Peter through the third. I know a lot of people don't want that to come until the third movie, but it really does need to come in the second if it's going to happen at all. The reason being: If it comes in the third movie, then you're left with no time to develop a relationship between Mary Jane and Peter. Additionally, it's just not a good idea to end a trilogy on such a down-note.
- Norman Osborn has to be in the second movie. That isn't to say he has to be the Green Goblin in the second movie though. I agree with a lot of people: Save Goblin for the third. Build up to it. TASM hinted at the idea of Norman being responsible for the deaths of Peter's parents - tie that all up with the third movie. It would be that much more satisfying of an ending if Norman is also responsible for Gwen's death.
- The primary villain has to be different than The Lizard. Another mutant won't excite audiences the same way the second time around. A friend of mine really wants to see Mysterio, and as cool as that might be to see on-screen, I'm not sure how they could do it and not draw the obvious comparisons to Batman's Scarecrow. Personally, I think Kraven is probably the best choice, especially if he is bank-rolled by Oscorp to hunt Spider-Man. I suppose that, if Sony is really so bent on the idea of doing a Venom spin-off, Venom could be the enemy of the second - acting independently whilst Norman Osborn poses the real threat in the background, still carrying on Connors' work as a set-up for the third film. Sort of a war on two fronts for Spider-Man.