Think even PS3 had a hypervisor.... but maybe only for the guest OS
Don't care what Corinne is doing at ND, as long as we get Elena in gorgeous 1080p and a nice honeymoon in e.g. Madagascar ;-)
The PS3 hypervisor is always there, even for games. It's lightweight compared to OS layers.
In PS4, developers don't have to worry about snapping with another app, naturally they only need to worry about making games on the target h/w.