By "multiple displays" I'm talking about app windows that are all around you in your space which you can move around as you see fit. You really should watch the promo video to help understand:
It's all controlled by your eyes and hands. There's no mouse cursor, instead your eyes (where you look)
is the mouse cursor. As an example, instead of having to tap/click on a speech icon to initiate voice input from a search bar, instead you just look at the speech icon and "click" it by tapping two fingers together. They've eliminated the need for a mouse by enabling the system to track your eye movement. The only situation I could think of where you'd really want mouse movement separate from looking is in gaming, but for general computing use it's amazing.