"The only exception is when the lines do not exist, or are not visible, in which case the driver will have to take the old-fashioned route and drive with both hands."

That sounds like a severely limited AI.

I wonder if some of these half solutions won't actually be worse for safety. Is someone a great deal more likely to completely shift attention from the road if the car is driving? Maybe even by dozing off? When that happens, how long will it take to regain sufficient focus if the white lines disappear on a stretch of road? How robust is the AI for a car that could be fooled by deceptively-painted lines?

Google's car is much more sophisticated. Given what Google has demonstrated, I'd rather we skip any intervening generations of half-self-driving cars. These pseudo driving cars seem just as likely to give the whole AI vehicle concept a black eye and set the industry back 10 years.