For those who say it will never take off... you never know!
Look around, many things had become reality as technology advances, and we (or people in tha past) thought they were joke! This invention/evolution might not seem pratical today but we may look at it differently after a long improvement.
and about FAA, new rules must be in place, just like we keep updating every other rule. When cars invented 100 yrs ago, would anyone expect to see traffic light coming in our way? I'm sure that not just the new rules, vehicle sensors and controlling equips will be different requirement, too.
the movie Blade Runner is a more realistic example. It may not fly fast (to run very fast still in car mode) but it provides conveniences in 3D space living in a metropolis city. some criminals may take advantage of it, but so does the police cars.