I just discovered two new books mentioned as upcoming on Amazon (not dates or ISBN, hence no link here).
The first one is a "no-brainer": The Imagineering Field Guide to Disneyland. The other 3 volumes in the series were good and I am quite looking forward to this one.
The second book is more intriguing. Its title: Hippo in a Tutu: Dancing in Disney Animation by Mindy Aloff.
On here site, the author says: "Am working on Hippo in a Tutu, a book about the dance sources of historic Disney animated films, for Disney Editions."