We get some details on Harry Osborn in Amazing Spider-Man 2 from Dane DeHaan talking about the origins of the villains in the movie.
Three villains (at least) we know of include Dane DeHaan as the Green Goblin, Jamie Foxx as Electro and Paul Giammatti as The Rhino.
We see DeHaan mentions that the villains rise from OsCorp, and we've already seen teasers referencing Vulture, Venom, Morbius and Doc Ock. DeHaan also mentions specifics about his character.
Via Digital Spy:
When you first meet Harry he's just graduated from high school, and he has to come back to New York to help deal with Oscorp, and its legacy, and his father [Norman Osborn, played by Chris Cooper]. He also sees Peter Parker for the first time in a long time; they were childhood friends. So it's really about Harry having a friendship with Peter and an allegiance to Peter, but also being the heir apparent to Oscorp, and having to deal with that.
It's becoming very obvious that all of these villains are originating from within Oscorp, in one way or the other. There are things that Harry feels he owes Peter, and things he needs from Peter, there are things he feels he needs from Spider-Man, and then there's his responsibility to Oscorp. It's a very complicated storyline, really cool and dynamic.
Another bonus is that DeHaan mentions he and Parker already have some history, so they won't have to totally rehash what we've already seen in the Raimi Spider-Man films.
The "Amazing Spider-Man 2" swings into theaters May 2nd, 2014 directed by Marc Webb starring Andrew Garfield, Emma Stone, Jamie Foxx, Dane DeHaan, Paul Giamatti, Felicity Jones, Colm Feore, and Chris Cooper as Norman Osborn.
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