At a stroke, Cupertino has removed the Kindle's one unique selling point and paved the way for a sweeping success for the iBookstore. With 100 million iOS4 devices out there, there is absolutely no chance of the iBookstore being a flop unless the pricing structure is obviously unattractive, which I seriously doubt. Indeed, if any proof were needed, Apple claim to have captured 22 percent of the ebook market in under two months.
As I've been saying for months, portability and syncing is what the ebook market demands and to have two such major players, Amazon and Apple, committed to synchronisation represents a turning point in ebooks. We are getting a glimpse of the future.