Can already do this with Android. See below. I'm running an Ubuntu overlay theme (UCCW with Nova launcher) with an AOKP ROM that uses Ribbons for swipe navigation and multitasking.
First image is my home screen. 2nd image is swipe up for dock. 3rd image is swipe from right side edge for favorite apps and recent apps (instead of using a ribbon though, I use n app called Swapps). 4th image is swipe down for notifications, toggles and Nav bar, plus virtual power button.
I could also use swipe from left side, but don't need it. I have no need to use any physical buttons, other than to turn the phone on. All swipes are available at any time unless in an app that prevents input, until it is exited.
I look forward to the real thing though, when it actually is in a working beta state, instead of the very raw alpha currently out.