While his role hasn’t been confirmed, he is thought to be taking on the role of Falcon, an excellent trainer of wild birds who has an ability to control and talk to them. The character also has a wing harness which allows him to fly.
At ComicCon the title for the sequel was unveiled, and suggested Bucky Barnes, played by Sebastian Stan in the first film, will return as a brainwashed Soviet assassin known as the Winter Solider. In the comics Falcon, real name Samuel Wilson, was trained by Captain America and served as his partner to track down the Winter Solider, so his inclusion in the film makes sense and his powers will be interesting to see on-screen.
Anthony and Joe Russo, two brothers who have direct episodes of Community and Arrested Development, were recently chosen to direct the sequel, and Captain America: The First Avenger screenwriters Stephen McFeely and Christopher Markus wrote the script.