Prometheus sequel guarantee?

Hi everyone, I just got done flipping through my copy of Prometheus the art of the film i got today. On the last page is a quote by Ridley Scott, "I thought Prometheus was so enjoyable - returning to the world of science fiction was so fun - I'm thinking about what the hell I might do for a Prometheus 2..." Now it seems to me like this could be a significantly big piece of evidence that supports the notion of a sequel, for the reason that it is in print in a book about the movie that was came out after the movie was released. What do you guys think?