Maybe Apple will do this with their forthcoming iPad
You're absolutely right.
I recently had a paper book published: the publisher will give me 10% of the price they sell the book for, which is typically 2/3 of the list price, so I'm getting about 7% of the list price. As I understand it, authors typically get between 5% and 15%.
We specifically left eBooks out of our agreement because the publisher hasn't decided what to do about eBooks yet, and I think the author should get a bigger cut from an eBook. We'll see what happens.
Maybe Apple will tap into the huge market you have identified.