Not sure if a "quadcopter" is a technology that can be used for passenger carrying aircraft. Too many disadvantages, and hardly any of the advantages would carry over to a full size machine.
For example, the aerobatic capabilities would be severly limited by the limited strength of the airframe and rotor systems of a full size model.
At the same time, redundancy requirements for engine and systems failures would make the thing very complex and heavy.
I am sure we'll see a lot more of these things in the future in the form of smaller UAVs though, taking over some of tasks for which conventional helicopters are used today.
Have a look at these guys here:
Luftaufnahmen mit DEDICAM.TV This is not autonomous yet, but I'm sure it will be soon enough.