Apple's textbook dream a false dream?

There's a very interesting exploration of Apple's ideas for a textbook revolution over at ZD-Net, which draws attention to some of the real problems associated with the idea of handing out iPads to all kids in the US school system.  Most of the discussion that follows doesn't really take issue with the basic arguments, other than to suggest that the suggested cost of $27.5 billion for the hardware is pretty insignificant given that the total cost of K-12 education in the US is $536 billion - forgetting the crucial question, What do you stop doing in order to spend $27.5 billion.  Personally, I think the arguments against using the iPad are pretty strong and I suspect that the real market for books created with iBooks Author is going to lie in higher education, business and industry.  The typical book in these areas is not going to sell as many copies as, say, a new algebra text, but it will be a very quick way for authors to get their books into the market place.