When Joss Whedon took the job as director of "The Avengers," he had a specific challenge to overcome. Even after the success of the individual movies featuring Iron Man, Thor, and Captain America, it seemed like a nearly impossible task, juggling so many giant personalities in one coherent story.
Now the challenge is very different for him as writer/director, because he's following up one of the biggest films of all time, and he's also laying groundwork for the entire next phase of movies in the Marvel Cinematic Universe. The last time a director found himself in a similar position with Marvel was Jon Favreau on "Iron Man 2," and it's interesting to see the ways Whedon has responded differently, and the ways in which he's fallen into some of the same traps. Make no mistake… "Avengers: Age Of Ultron" is both a better film and a better sequel than "Iron Man 2," but I think it's clear at this point that as long as Marvel continues to build one large interlocked continuity, there are certain stumbling blocks that they will continue to face with the movies.