When I will be able to buy a sky car?
What is your disposable income? How convenient is it for you to access an airfield near your home and common destinations? Depending on your answer to these questions, the answer may be, "Now", or "In 30 years".
Not so helpful toward the spirit of the question.
I think you need to think of this in two ways.
1) Flying cars like THe Jetsons - The regulation alone would have to put this so far beyond anything we could predict it would take all meaning out of it.
2) Hovering Cars - I would like to know the answer to this one.
"Flying cars" as they exist now, are more akin to planes-that-can-drive-on-roads
Exactly. "Roadable aircraft" is the common term, and it makes sense ... given how easy it is to acquire a drivers' license, do you really want the same people flying a plane?
Here are some actual specimens, in production (google search any of them and you'll find neat videos, too):
Terrafugia Transition ...
http://www.terrafugia.com/aircraft/transition
It's flown for years, runs on super-unleaded, and with folding wings can park in most people's garage. It's been to Osh Kosh numerous times.
Their upcoming TF-X model looks interesting, though I fear it may be so complicated that it'll have a harder time reaching market.
ITEC Maverick ...
http://itecusa.org/maverick.html
Ever see / hear of the movie "the End of the Spear"? The protagonist has a heart for helping * people living far from civilization, and one way is with (what I call) flying dune-buggies. Also been flying for years, in production, and quite durable.
* actually helping, by the way: providing knowledge, medical assistance, eye exams & services, dental exams & services ... all in a non-profit / volunteer fashion.