Here's what the filmmaker had to say about possibly saving the villain for the finale, The Avengers 3.
"Well, Thanos is more powerful. He is so powerful he is not someone you can just try out and punch him. Like he did in the comics, you want him to be threading through the universe and to save the big finale for 'the big finally'. He is definitely a part of what I have got going on. The thing about the Avengers is that they are very powerful but not very stable. So, there will definitely be some people that will shake them up in the next installment."
"I am not the guy who should worry about him being replaced. He is Iron Man at this point. When I heard that he was cast I just knew that something had changed, and I don't usually know stuff like that. I said 'Now we are in a new phase.' The way he embodies it... I love working with him. (Iron Man 3 director) Shane (Black) captures it so perfectly in this movie. I want him to play it forever. The thing is that he has a flying metal suit. It Is not like in those Charles Bronson or Roger Moore movies, when you are like 'Dude, you can barely stand.' He's got some fight in him. At the same time, if Robert decides to hang it up, he has a perfectly good excuse."
If Thanos isn't the main villain in The Avengers 2, who is? What do you guys think? Who do you want to see going up against the Avengers as a team when they return in 2015?