This is about size. It would be great if there is a material that could be squeezed to a smaller size if the iPhone is not in use. To give its initial size back, you just have to "shake" it.
iPhone with holographic display doesn't need a big casing anymore. You can carry it on your wrist.
With wireless technology iPhone could become more communicative with each other. You can imagine what kind of great features could show up one day.
