In a recent interview with Digital Spy, Dane DeHaan discussed Harry Osborn's character arc in Marc Webb's The Amazing Spider-Man 2. I've always like this character, and I'm looking forward to seeing exactly how he'll be portrayed in this film.
"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."
From the trailers we've seen for the film, we know for a fact that Harry will be the Green Goblin, but it sounds like things will be even more complicated than that, which is awesome! Crazy complications always make for a more interesting story.
The movie is set to be released on May 2nd, 2014.