The full-length trailer is out for the upcoming Japanese anime adaptation of Mary Pope Osborne's mega-popular Magic Tree House books. The film will open in Japan on January 7, 2012, and I suspect it will turn up in American theaters eventually. This series has sold more than 92 million books worldwide, so it seems like it would be well-worth the cost of dubbing... unless, of course, there's already a competing English-language edition in the works*.
*There isn't, as far as I know. But give it time.