I am pretty skeptical about self-driving cars, for the simple reason that we don't even have self-driving trains yet, outside relatively small systems like the DLR, Heathrow Pod, etc, and it would seem to be that the job of driving a train (no steering, no collision avoidance, predetermined stops, etc) would be 100x easier.
There are actually quite a few driverless trains already[1] and Google's demonstrations of their driverless car are getting increasingly[2] impressive[3].
The question is really only when the transition to driverless cars will happen - we're long past the if.
