Here's what the filmmaker had to say below.
"There's so much we could do... The ideas I've had are all sorts of things, ranging from Full Metal Jacket with apes... you could start this story again eight years from where we left off, the next generation of apes, those that have come from our protagonists, perhaps going in to a conflict with humans and showing real fear, in the same way as going into war for young soldiers in this day and age, telling their story. Or how apes are taking over cities, and being moved into human environments and having to interact with them and deal with things that are part of our culture and understand and evolve through them. Spies that are in the employ of the apes, working against humans and humans maybe existing underground, because that's a way they can avoid the virus, coming up above ground wearing gas masks, and maybe that's what dehumanises them."
A sequel hasn't been green lit yet by 20th Century Fox, but with a strong opening weekend under its belt, don't be surprised to hear about Rise of the Planet of the Apes 2 in the near future.
Rise of the Planet of the Apes was released August 5th, 2011 and stars James Franco, Freida Pinto, John Lithgow, Brian Cox, Tom Felton, David Oyelowo, Tyler Labine, Jamie Harris. The film is directed by Rupert Wyatt.