The big advantage over a monitor is immersion. When I tried out an oculus rift I felt like I was inside the virtual space in a way that I've never felt while playing FPSes on a monitor. That's not a small thing.
Another advantage is that it increases how many input axes you have. Think of games where you're flying a spaceship or driving a car and you can freely look in all directions while controlling your vehicle with both hands. That's impossible on a standard monitor.
It's not impossible. Games frequently allow you to use the arrow keys to move around while using the mouse to change the view direction (or vice versa).
It's time to look back to see what was predicted a year ago and how successfully it was.
But even more, it's time for the fresh predictions for the following year, 2014.