I personally believe that even the Tesla at this point is safer than a drunk driver. On a highway, with limited access, and all the traffic going the same way, the humans may become distracted, but the occasional boat falling off a trailer and skidding across the road, or deer, moose, etc might not be as well handled by the Tesla. Deer seem to be particularly suicidal, and Tesla doesn't seem to have taught that to their AI yet.
I'd say we're a decade or two from having actual statistics that indicate an AI driven car is as safe as most people. How far Elon can warp reality to move that number forward is going to be interesting to watch.
Unlike Fusion, I see no actual technical reasons it can't happen... it's just a matter of software.