Hawk pair: Johansson's Black Widow and Renner's Hawkeye have a nicely intense chemistry as pals of "The Avengers." Amidst Marvel/movie regulars that include the archery-astute Hawkeye (Jeremy Renner), Agent Coulson (mild-mannered standout Clark Gregg ) and Iron Man assistant Pepper Potts (Gwyneth Paltrow), Harry Dean Stanton also becomes especially memorable in a