"It was this kludgy prototype the first time," said Cameron of the first film. "We always knew as we were going along, this isn’t really working, but we’ll fix it for the sequel. The first film just about killed us, and now we’re gonna try to do twice that much."
If the technical aspect wasn't enough reason for the delay, Cameron also said that writing two scripts is hard work. "It’s a little bit of a daunting writing task because it’s two scripts and they’ve both gotta be done at the same time," said Cameron about "Avatar 2" and "Avatar 3," which will be shot back to back. Cameron also admitted that the writing process is more difficult because he doesn't want to run the risk of creating another "Matrix: Reloaded."
"I’m writing it as separate stories that have an overall arc inclusive of the first film," Cameron said. "I don’t want to suffer from the 'Matrix 2' problem, where it just ends, like, what the hell? It’s gotta end. There’s gotta be a sense of conclusion, but also a sense that the journey will continue, and that’s a fine line." How the potential fourth film, set to be a prequel, fits in isn't clear at this point, but it's probably many, many years away, with the long-gestating "Battle Angel" likely to follow the second and third "Avatar" films.