Fans of the character will have no doubt noticed that The Incredible Hulk set up not one but two possible adversaries for the Hulk to battle in the sequel. Besides the omnipresent threat from the military and a possible return of the Abomination, either Samuel Sterns, aka The Leader or Leonard Samson, aka Doc Samson could battle Marvel's mightiest hero. And according to what Louis Leterrier told MTV, he thinks that the decision should be made by the fans.
"I think that if we get to Hulk 2 I would go to Comic-Con and ask the crowd of people that actually love the movies, which one would you prefer to see, Samson or the Leader?" Leterrier said.
In the comics, both Samuel Sterns and Leonard Samson become gamma powered characters themselves. Samson ends up with superhuman strength and durability (and green hair), and becomes a part-time superhero in his own right. Sterns acquires increased mental abilities in the form of a superhuman intellect and psychic abilities, along with a massively deformed head. When we last saw Sterns in The Incredible Hulk, elements taken from Banner's blood were dripping into the cut on his head, and the skull was visibly distorting, which makes the Leader the character who would be easier to bring into the next film.
Leterrier has stated that, if it were entirely up to him, he would pick the Leader on the basis of it being a different kind of enemy for the Hulk to fight.
"Both [the Leader and Doc Samson] are very interesting. [But] there's something unstoppable about [Leader] and it's just not the same thing. It's just different." Leterrier said. "The fact that he controls stuff with his mind, I just like that."
Of course, Marvel has yet to announce concrete plans to move forward with Hulk 2. Additionally, Leterrier has stated that he believes that possibly the next time we see Bruce Banner and his green-skinned alter ego, it won't be as a hero, but instead he will be the threat which forms the superhero team of The Avengers.