Personally, I think the most interesting one is producing a son with his DNA and Sydney's eggs...but it looks like they scratched that one.
But what people don't realize is that the chosen one has already fufilled her duty--by retrieving the rose. That's why Peyton gave the order to kill her--she was useless at that point.
Also, I have a feeling, considering the final hour is titled "All The Time In The World", it's a substance that makes you immortal. I hope not though.
