What's interesting about the Phase Three films that Marvel is planning to make is that they are all going to have to be fairly focused on moving major story elements forward, considering what happens to the team at the end of "Avengers: Age Of Ultron." If the first film was all about building the team for the first time and proving that they could work together, it was also about Thanos testing Earth's defenses so he could figure out what he was up against. "Age Of Ultron" is more focused on each of The Avengers having to deal with the results of actions we've seen from them in earlier films, with some serious fall out on every front. By the end of the film, the team that we saw in the first film will be shattered. There will still be a group of people called The Avengers, but it's not going to be Thor, Hulk, Iron Man, and Captain America anymore. The third film will have to bring everyone back together to stand against Thanos as he finally makes his move on Earth, and considering how many of the Infinity Stones he'll have by that point, I'm not sure how anyone's going to plan to stop him.