[turtle4]

It is a touch screen. It is used for user interaction. You can swipe it to scroll through your books, but I'm sure it can be/is used for other things. Display keyboard to enter search terms, etc.

Apple detailed the many benefits of this when people complained about the iphone not having actual keys. It makes the device more flexible. Want to use the device in English and Korean? No need for a different device, just display the different keyboard.

My only negative thought about it is that the color screen has got to be a bigger eater of battery than if they had gone all hardware, ala kindle, but I don't know if it is really an issue or not.