The next Studio Ghibli movie is based on the novel The Borrowers and is being directed by Hiromasa Yonebayashi, who until now had been an animator. The Borrower Arrietty is his first movie as a director. The funny thing is that even though it is based on the novel by Mary Norton, the action of the movie takes places in Koganei, a neighborhood in the western part of Tokyo, where the headquarters of Studio Ghibli are located. I usually ride my bike around the area on weekends.
More information at Ghibli World.