Apparently, Eve and Hayley Atwell (Cassandra's Dream) "are screen-testing for the second time for the coveted role tomorrow in London." The story goes on to report that Keira Knightly is no longer in the running.
Not much more is known about this casting rumor at this time.
Captain America: The First Avenger was released July 22nd, 2011 and stars Chris Evans, Hayley Atwell, Sebastian Stan, Tommy Lee Jones, Hugo Weaving, Dominic Cooper, Richard Armitage, Stanley Tucci. The film is directed by Joe Johnston.