1) Will all the textbook publishers even buy into this? They didn't give much indication at their speech (there are more publishers than McGraw Hill), but it seems hard to imagine they are happy about going from $90/book to $14/book. What's Apple's cut on these books? 30%? Less? Loss leader to sell iPads?
2) This will widen the gap between rich and poor students. The rich ones who can afford the iPad will get the purported better education through interactive books while the poor will be left behind with the old text books. Don't give me the "well now students can buy an iPad cause books are cheaper" thing either - kids in high school don't pay anything for books.
3) eBooks are mighty small when compared to other products for Amazon and Apple. It looks like January 2011 was about $80M. By comparison, Apple's revenue is over $100B/year and Amazon's is $36B/year.