In movie 3 the fate of the characters should be:
Harry- Dies in battle. He dies sacraficing himself for Peter after forgiving Peter, and realizing that Norman's death was Norman's fault alone.
Aunt May- Lives on to see another day. Makes complete peace with Peter for death of her husband. However, is shunned by "dark Peter" throughout the film.
Mary Jane- Lives to see another day, as well. She and Peter break up in the middle of the film. "dark Peter" ditches her, and is with Gwen. MJ later learns that his actions were just a result of the symbiote, and once she sees the evil that the symbiote realy holds (Venom) she believes and forgives Peter.
Eddie Brock/Venom- Venom "dies". Not anything of any finality, just Brock and the Symbiote seperate, and Brock is left a broken man, out for revenge. Making him even more dangerous when he reunites with the alien and "I" becomes "We" once again.
Sandman/Flint Marko- Dies as a result of Venom turning on him in the final act.
Gwen Stacey- Used as bait to capture and kill Spider-man by the Green Goblin. She is dropped from atop a building and dies in Harry's last act of evil.
Captain Stacey- Dies in the result of a Goblin or Sandman/Spider-man fight. An explosion occurs during an ariel/building top battle, and bricks and debris piles on top of the police captain, killing him. Gwen blames Spider-man for death of her father, but doesn't know that Peter and Spider-man are one in the same.
Peter: Left in complete agony after the death of the only other woman he has cared for his entire life, and the demise of his best friend, who died in one last act of heroism.
-R