I can admit The Avengers wasn't particularly interesting or groundbreaking in the cinematography department, but at the same time... it didn't need it to be. That movie worked because it was something that hasn't been attempted before, playing with all this different pieces from previous films, making them work together, jamming all this personalities and powers and ideals. It's an adventure film, a superhero team up that is just perfect at what Marvel and Whedon aimed for it to be.
Now, knowing how Marvel Studios is getting not just bigger but more confident about themselves, I know they're getting more ambitious and that will surely translate in Age of Ultron. The novelty of this superheroes together isn't as fresh as the first time, so I'm sure they're going to compensate it with another tone.