Marvel wants Aaron Taylor-Johnson for the role of Quicksilver in Avengers 2, according to Deadline.  Taylor-Johnson is best known for his role in Kick-Ass and Kick-Ass 2.  Director Joss Whedon has said that he wants Quicksilver and Scarlet Witch in the film to keep it "fresh" (see "Quicksilver and Scarlet Witch's Powers Will Keep 'Avenger 2' Fresh"). 

Evan Peters ("Todd" from Kick-Ass) has been cast as Quicksilver in X-Men: Days of Future Past (see "Quicksilver in 'X-Men: Days of Future Past'").