So every Avengers fan is currently confused and thinking... Which side is the Scarlet Witch going to be on? Will she side with Iron Man's team or Captain America's team?
The recent interview with Elizabeth Olsen (who plays Wanda "the Witch") did not reveal much information. Elizabeth was coy when she was asked whether her allegiances would be with Robert Downey Jr's Team Iron Man or Chris Evans' Team Cap. She said that Wanda is "always the wild card", so there's no telling which team she will play on in the movie.
The upcoming Captain America Civil War movie will focus on the Government trying to regulate and control superheroes following a major disaster or event which involves someone with powers. This will bring Iron Man and Cap into conflict. Iron Man is more for the government regulating superheroes, whilst Cap insists on individual freedom.
The other Avengers will therefore be equally divided into the two camps.
Some gossip has placed the Scarlet Witch in Team Cap, since she would be closer to Cap considering that she will be trained by him (as seen in Avengers 2). Also as we saw in Avengers Age of Ultron, Wanda had issues with Tony Stark, since she (and Quicksilver) blamed Stark for the death of their parents.
So it is very likely Scarlet Witch will play for Team Cap.
On the other hand, following another interview, Elizabeth Olsen stressed that the Witch is a wildcard, and that there is no guarantee that she will be a "hero or villain". So maybe she won't be on either side!