From the description and the images from the manga (above), the film seems to have similarities to the director's 1992 "Porco Rosso," which focused on a 1920s bush pilot who looked like a humanoid pig.
Miyazaki's last film was 2008's "Ponyo." The director won a Best Animated Feature Oscar for 2001's "Spirited Away," and was nominated for 2004's "Howl's Moving Castle." "Spirited Away" still holds the title of Japan's all-time biggest box office hit.
Repertory theater audiences in select cities were treated to the Studio Ghibli retrospective touring program this past year, with a number of Miyazaki titles screening in new 35mm prints.
Japan's top distributor Toho will release "Kaze Tachinu." No word on US distribution.