Can you imagine how many accidents there would be with flying cars... people zipping around all over the place. I think what is more likely is something similar to what you see in iRobot - cars that drive themselves at a locked speed etc. I mean, they've already developed cars that can parallel park themselves.
I think we're likely to see mass production of self-driving cars sooner than we will see flying cars.
Well for one thing, they would need a (much harder to get) license. However, I was thinking of something more along the line of flying cars running autopilot.
The problem with your idea (and mine) is that there si no AI advanced enough to make the decisions. Even in airplanes, there may be autopilot but it is never used to actually land, takeoff, or in emergencies. Also, we would need some kind of reliable mass communication for all the cars to 'talk' to each other in order to properly drive, traffic lights, e.g.