I'm sure logistics regarding batteries and charging will be resolved pretty quickly but how the routes will be planned and issues over safety will be more difficult.
With this and the Facebook trials with internet drones it's interesting times.
http://www.thetimes.co.uk/article/amazon-is-closer-to-delivering-by-drone-r2cdnrwd7?shareToken=9b3f8a76252dcc775c21003067880911