For "The Avengers 2". Yeah you read that correct, Joss Whedon himself has confirmed that Quicksilver and Scarlet Witch will feature in the film.
"You know, they had a rough beginning. They’re interesting to me because
they sort of represent the part of the world that wouldn’t necessarily
agree with The Avengers. So they’re not there to make things easier. I’m
not putting any characters in the movie that will make things easier."
It was kind of obvious that these rumours would be confirmed at some point, but the question is how will they be included in the film? Are we going to see them in X-Men related films? Will we see the as "easter eggs" in Marvel films? It is far to early for me to speculate on who could play these characters, for one the film is soooo far away and another I know nothing at all about the characters. I will do a little research an get back to you guys and girls.