Joss Whedon Hints at Scarlet Witch and Quicksilver in পরবর্তি Avengers Film 

PLEASE no Ultimate influences, other than a few uniforms. We definitely don't need a repeat of the Wolvie bushes scene! Anyway, I believe bringing them into the mix would be a fantastic idea not only to have another great Avengers installment, but to also bring mutants to the scene with a blessing instead of a curse upon their heads with another movie. Not only that, but it could also be the beginnings of a separate and better X-men franchise if they would just let the current one rest for a bit, so as not to confuse everyone too much. Besides, I think with the right actor and actress, the twins could have a wonderful debut to the big screen.