Ultron will get an entirely new origin story in The Avengers: Age of Ultron.
In the Marvel comic books, Ultron is considered to be one of the greatest creations of scientist Henry Pym, a.k.a Ant-Man. The sentient robot is dedicated to eradicating the human race once and for all. The robot's violent tendencies are said to spring from both Pym's intellect and mental instability. The character is the subject of a recent 10-issue limited series that envisions a future where Ultron has layed earth to ruins and has forced all of the superheroes underground.
In The Avengers: Age of Ultron, Hank is no longer the creator of Ultron.
"Well, because there was a book called 'Age of Ultron' quite recently, a lot of people have assumed that is what we're doing, but that is not the case. We're doing our own version of the origin story for Ultron. In the origin story, there was Hank Pym, so a lot of people assumed that he will be in the mix. He's not. We're basically taking the things from the comics for the movies that we need and can use. A lot of stuff has to fall by the wayside."
It has been speculated that Tony Stark might be the creator of Ultron. Joss Whedon continued to explain.
"We're crafting our own version of it where his origin comes more directly from The Avengers we already know about. It's a little bit darker than the other film because Ultron is in the house. There's a science fiction theme that wasn't there in the other one. Ultron is definitely something that evolves, so we're going to get together a couple of different iterations. Nothing can be translated exactly as it was from the comics; particularly Ultron."
When asked about the scale of the movie, the director had this to say.
"It's very much a global Avengers film. A lot of the movie has to do with their place not just in America, but the world. Part of the fun for me, definitely this time around, is writing Hawkeye. He did get possessed pretty early by a bad guy and had to walk around all scowly for most of the movie so now it's nice to actually have the character there and see him interact with the other guys."
Avengers: Age of Ultron comes to theaters May 1st, 2015 and stars Aaron Taylor-Johnson, Scarlett Johansson, Robert Downey Jr., Elizabeth Olsen, Chris Hemsworth, Chris Evans, Cobie Smulders, Jeremy Renner. The film is directed by Joss Whedon.