Director Edgar Wright (Shaun of the Dead, The World’s End) is leaving Marvel’s Ant-Man. Here’s the statement from Marvel and Wright announcing his departure (via The Wrap):
Marvel and Edgar Wright jointly announced today that the studio and director have parted ways on Ant-Man due to differences in their vision of the film. The decision to move on is amicable and does not impact the release date on July 17, 2015. A new director will be announced shortly.