Rumors are swirling the internet on what exactly we will see in this new build. I would expect expanded abilities to take notes, annotations, highlights as a couple of new features to be enhanced. Apple may also take elements out of Amazon’s playbook and give support for music and audiobooks via iTunes within iBooks.
The only thing we know for sure is that iBooks 3.0 will have EPUB 3 support.
Via Chuck Hitchcock, Jenny Smith