Summer 2015 is going to be "Marvel"-ous with not only the end of "Phase Two" with The Avengers: Age of Ultron on May 1, but it will also be the beginning of "Phase Three" with Ant-Man on July 17 instead of July 31, according to Deadline.
July 17, 2015 was supposed to be the release date for Batman vs. Superman, Zack Snyder's sequel to Man of Steel with Henry Cavill and Ben Affleck as DC Comics' yin (white knight) and yang (dark knight) of superheroes, but it has been pushed back to May 2016.
Ant-Man stars Oscar winner Michael Douglas as Henry "Hank" Pym and Paul Rudd as Scott Lang.
In the comics, Ant-Man was preceded by pacifist Pym, a scientist who is one of the founding members of "Earth's Mightiest Heroes" known as The Avengers. He was responsible for the creation of the evil robot Ultron, who tried to take over the world through his own creation: the android Vision, who turned against Ultron and joins the Avengers. Ant-Man was then succeeded by electronics genius/ex-thief Lang, as Pym went on to become several superheroes -- most notably, Yellowjacket.