We know that Chris Cooper plays Norman Osborn, the father of Dane DeHaan's Harry Osborn in The Amazing Spider-Man 2, and it was rumored that the character will be sticking around for The Amazing Spider-Man 3 as well. During an interview at the Toronto International Film Festival, Chris Cooper confirmed that The Amazing Spider-Man 2 sets up Norman Osborne to return in The Amazing Spider-Man 3.
"Well, this is an introduction to Norman Osborn and apparently this leads to better things in Spider-Man 3. I think it's fair to say he's on his last legs...I don't know if I can say anything more!"
We reported in June that the Green Goblin will make an appearance during the final battle of The Amazing Spider-Man 2, but it is actually Harry Osborn who will turn into the villain, instead of his father. Since Norman is on his "last legs," isn't known how the character will fit into The Amazing Spider-Man 3 or The Amazing Spider-Man 4 storylines, although it will likely have something to do with handing his Oscorp company over to his son.
This sequel is taking a major departure from Sam Raimi's original Spider-Man, where Norman Osborn was the Green Goblin (Willem Dafoe) before being killed by Spider-Man (Tobey Maguire), leading Harry (James Franco) to continue his father's evil legacy.