For 1, it was all pre-recorded and edited. So, let's just shatter that dream for everyone.
However, they DID actually do it and said that it could be done live and I guess Disney Land/world has a nightly show that uses something similar?
Intel I guess makes these particular drones specifically for this purpose, but I didn't find any details on precisely what they used. I would guess it's GPS for the rough positioning and then it must be a mesh type network of sharing sensor data and then sensors (sonar perhaps?) To get better precise locations.
Or maybe they have to place "beacons" on the ground in precise locations to give sort of a "local GPS" mapping?
In any case, it was really really awesome