1. Comments that it is not Peter are lies and it is Peter whose powers have altered, or he is wearing special boots/gloves to have "claws"
2. Morbius did bite Spidey, perhaps that bite combines with his Spider powers and alters him
3. Spider-man 2099 comes to our time and takes over.
4. Ock pulls a mind switch but something happens and they merge (hope not)
5. Phil Urich or Kingsley decide to take up the identity. Kingsley did take the Green Goblin identity and update and adjust it to his specifications and arose as the Hobgoblin, then he was recently seen in South America as the Devil_Spider, which is said to be his version of the Tarantula. (and the name feels like a shot at all who hate the Mephisto Mindwipe). Perhaps Kingsley survives the Goblin War and decides to retire the Hobgoblin again and suit up as Spidey? I could see him doing that more then Phil who is just bat-crazy
6. jackal captures Peter and unleashes a new clone of him. Hate to even think of this but with that idiot running around cloning himself ad nauseum and still obsessing over Peter this is a possibility.
I think what will happen is that the Miguel thing is total utter lies, a con, a trick, a joke. I think something is going to happen to make Spidey have to fake Parker's death. I think he will be in some way mutated too, which might explain why his life will be different as Spidey. Four eyes? etc?