Maybe not holographic projections, but I think it is pretty likely that we will be able to to basic things like open apps, scroll, type, etc, without touching the phone and making traditional finger movements on a screen. A sensor on the device will be able to perceive more complex motions we make with hands and fingers which will allow these tasks to be done more quickly, and with less effort. Likely there will be more attempts (like google glass) to improve the visual aspect of handheld devices, but it's hard to speculate about what that would look like since most people thought google glass was a cool idea at the time, but they turned out to be completely impractical. Just my thoughts