Well, this is sure to be an upset to the market. Amazon is going to allow developers the ability to offer in-app purchases to consumers for physical items that will be shipped to their homes. It's a little unclear yet if it will be limited to developers with products already on Amazon's website, or if Amazon will merely facilitate the transfer of shipping information. Could developers include in-app purchases of a physical product that they will handle distribution of themselves? That could be a huge boon for independent merchandise sellers, but obviously carries with it some inherent complications.
One of the first partners to offer products will be Activision, selling Skylanders characters.