This is why I'm excited for VR. Now that equipment like Oculus Rift is going mainstream, there's an opportunity to move beyond managing "windows" to managing "objects", e.g. taking a phone call would not affect the notes you were arranging on the virtual desk in front of you. Current generation phones are trapped by the limited screen size of a handheld device.
Even worse than being disrupted would be if my phone started trying to guess what I was intending. "It looks like you're writing a letter."