Welcome to SEMTEC! Home of SE MN Educational Technology Leaders!
Apple just released I-Books for Mac. I believe I-Tunes U will be soon to follow this will give the mac the tools needed to deliver a rich classroom experience. I-Books has been available for the I-pad and supports the e-pub3 format which allows integration of videos, 3D animated graphs etc. (not just a pdf version of a book).. Together with I-Tunes U teachers would have the ability to integrate e-books directly into their courses. With I-books author (free with Mac) a teacher can import something like a CK12 textbook and add their own lecture via youtube or mp4 throw in a 3D graph to create an awesome textbook.
Check out all of the stuff on the WWDC 2013 podcast in the I-Tunes store.