SCI FI Wire talked to Fantastic Four and The Silver Surfer screenwriter Don Payne, who said that he will develop Mr. Fantastic more:
"I think the one thing I really want to do is make Reed Richards, that character, smarter and tougher. He's the leader. I think Ioan did a great job [in the first film], but I think he could have had more stuff to play as the leader. Reed Richards has his nerdy side, but he ultimately has to make some tough choices."