What is being talked about is not autonomous, but automatic driving.
Autonomous: acting independently.
Automatic: working by itself.
The former implies that there is no driver or he's not in control. In the latter, the driver may delegate some or most driving tasks to the machine, under his supervision and responsibility.
This is "simply" an evolution from what we can see on the roads today with things like adaptive cruise control, dynamic steering, stability control, adaptive and predictive suspension, etc., etc., etc.
What happens is that in the process of adding more and more of these technologies, driving becomes a bit of a different animal compared to the old-fashioned (or motor sports) way, which is why the idea of a special licence is a sensible one.
My current car having many of the above mentioned technologies, I can attest that one needs to approach the driving in a significantly different way. I can also attest that it makes drivers not used to it *more* uncomfortable with the driving at first, especially if they haven't been briefed beforehand. However, once familiarised, the driving feels so much safer and relaxed--I would never go back to a "normal" car for day to day use.
Another interesting observation: I've been driven in my car by a number of different people from 19 to 40 years old, and I found the younger ones a) got hold of it a lot quicker, and b) drove a lot more sensibly (easier said than done with 420 HP under the bonnet!) than the 30-40 y.o., both men and women. Of course I don't claim my experience to be representative or significant, but wouldn't it be great if new driving technologies would make young drivers safer and more courteous?