Re: Avengers 2 and X-Men DoFP are both using Quicksilver and Scarlet Witch
Avengers 2 would have been rewritten anyway. Joss has only mentioned a first draft. At this point its just as likely that the twins are taken out as it is they stay in.
2014 Cinematic Adventures:
Noah | Captain America: The Winter Soldier | The Amazing Spider-Man 2 | Godzilla | X-Men: Days of Future Past | Dawn of the Planet of the Apes | Guardians of the Galaxy | Lucy