Replace "Amazon" with "Apple" with regards to music and other digital content. See a connection?
No one company should dictate an industry. As I stated earlier, Apple has done this with music and now movies. With $80+ in cash reserves and a strong consumer market and a dying print industry, of course publishing houses will jump into bed with Apple. However, it's either play by Apple's rules or get out.
Name one instance where Apple used it's dominance to enter a new market by undercutting competition? Apple neither sets prices in the ebook market nor do they demand exclusivity.