I feel in the next 20 years, the consumer drone industry will manufacture voice command micro drones that are fully autonomous. Launch and recovery will be completely hands free. They can deploy in a matter of seconds, operate indoor as well as outdoor, follow and track your movements, provide real time video, still photos, thermal imaging and even navigational aid through a smart phone app or possibly a smart watch. These "micro drones" will use a new battery technology that provides up to 4-6 hours of flight time. When many of these micro drones are operating in a specific area, they will establish a "network" that would allow other users to communicate, locate, request for help, send or receive messages etc. The drones will be about the size of a golf ball and all 4 propellers will fit inside the area of a common poker chip.
The real question is, where is the drone industry going with the defense industry? I feel that here may be self exploding micro drones in the near future. A drone that is similar shape and appearance to a large horse fly or even a large bumble bee that can land on someone's shoulder or fly close enough and "BOOM"!
As far as commercial drones. That depends on the FCC, DOT, DHS, and DPS that regulate things like these. A far as public safety goes. I don't foresee large packages being delivered via drone. Nor do I see humans being transported by drones unless the drone is operated by another human and there is something already like that- helicopters.