Update Friday December 20: Well, that was quick! Marvel, in a statement on Marvel.com overnight, made it official: Paul Rudd is the star of Ant-Man. They still have not, however, identified which of the three civilian identities who have held the role of Ant-Man in the comics will be the star of the film. Rudd is described as director Edgar Wright's "first choice."
“When Edgar Wright came to us with the idea of Paul Rudd, we felt a huge sense of relief because the first step in creating any Marvel Studios film is finding the right star," said Marvel Studios President Kevin Feige in the press release. "We knew early on that we had found the right person in Paul. When he not only agreed to do it but became as enthusiastic as any actor we’d ever met with about doing the work, we knew we’d found the right guy. We couldn’t be more excited for our audiences to see what he’s going to do to bring Ant-Man to life.”
Original Story: The next Marvel Cinematic Universe star is Paul Rudd. That's what trades Variety and Hollywood Reporter reported late Wednesday night, saying that Rudd has been pegged to star as the titular Ant-Man in the Edgar Wright-directed first film of "Phase 3" of the MCU.
Rudd, rumored for the role as far back as the late summer months of 2013, was believed to be a long-time front-runner with only Joseph Gordon-Levitt as the other possibility. It's possible, though unconfirmed, that JGL's commitment with Warner Bros for a Sandman film took him officially out of the running.
Interestingly, there is no official mention yet as to which Ant-Man Rudd will portray, though it's believed the script calls for the original. In the comics, there have been three, Hank Pym being the first and most famous in the role, and a founding member of the Avengers. Scott Lang was next, a reformed criminal who currently serves as the replacement leader of the Fantastic Four while Reed Richards and his family adventure through time and space. The third, Eric O'Grady, worked as an agent of S.H.I.E.L.D., which has of course been well established in the MCU.
Ant-Man is scheduled for a July 31, 2015 opening.