Amazon has backed down in the first war of Kindle pricing. Publishers Macmillan were furious over the huge mark-up that Amazon were changing for Kindle books. The row escalated over the weekend when Amazon decided to pull a pre-emptive strike and remove all the publisher's books including physical ones.
Macmillan is one of the biggest US publishers (imprints include Farrar, Straus & Giroux, Tor/Forge, Henry Holt, and St. Martin's Press) so pulling it was never going to be economically viable for anyone. The argument is about who gets to set book prices and prices for hardcover books. Amazon believes it should decide. Book publishers while book publishers say they are only a distributor and stop being so up themselves.