Joss Whedon's modern update of Much Ado About Nothing opened in Ireland today, and he did a press interview which mentioned his attitude towards The Avengers II:
From ComicBookMovie:
Responding to questions about doing more Shakespeare, Whedon says he doesn't want to do another one exactly like he did Much Ado About Nothing. He says that he needs to keep trying different things from a creative standpoint. From there, the discussion turned to The Avengers sequel.
Whedon: When I first considered doing Avengers 2, my first question was what can I do that's new? Because I can't make it bigger....but I can make it better.
The moderator asks about his philosophy for Avengers 2.
Whedon: Death, death and death. (Crowd applauds madly.)