"The climax that I pitched was completely unhinged and nobody said no, so that’s that." - Joss Whedon on 'Age of Ultron'

That bodes well.  Joss Whedon: Avengers: Age of Ultron’s Climax Is “Completely Unhinged” (Exclusive): "If you thought the New York-levelling finale of ‘The Avengers’ was huge, Joss Whedon says you aint seen nothing yet, promising an even more epic climax in the forthcoming sequel. “[‘Avengers: Age of Ultron’] got larger than the first film,” Whedon explains to Yahoo Movies.  “I didn’t mean for it to get larger, but the climax that I pitched was completely unhinged and nobody said no, so that’s that.”"