Naughty Dog's Justin Richmond has told SPOnG about the reason to move past Sully and Elena in
Uncharted 2: Among Thieves. It's to do with Nathan Drake's less seemly past.
"We put in these new characters Harry Flynn and Chloe Frasier, who are both from the darker parts of Drake’s past, and make a really nice foil to show off more of Drake’s personality than we did in the first game, and really show what he could have been.."
Read the full interview
here and read the Uncharted 2: Among Thieves review
here.