I went to a D23 program in Chicago last night that included a Q&A with Disney animator Andreas Deja. When asked about future hand-drawn animation projects, he told us that the directors of Princess and the Frog had their next project in mind, and that they are just waiting to secure the rights to the book (he gave no hints as to subject matter or title). Until then, there animators are experimenting with different things (he did not elaborable) so they will be ready to jump on the new project if and when rights are secured.