User blog comment:Captain James Rogers/Captain America: The Winter Soldier/@comment-4388254-20121208004108/@comment-1895174-20121208004624

We do know that Black Widow's going to be in the movie, though. I don't think there will be anything between the two in this movie (since Bucky might be too busy doing other titular things), but it's interesting that she's there in the first place.

I would say they're going to Cap's love interest, but another leading female role (presumably Sharon Carter) is also being cast.