This is nothing really new but something that is definitely overdue!
Given the background of my experiences at AENA and my studies, the video below (Source) which I found through Pogue’s Posts wasn’t actually much of a surprise for me but I think it gives a really good overview for non-pros! Besides, for me, it’s at least been a short update on the American state of the art and future plans as my personal knowledge tends to be a bit focused on the European on-goings.
For those among you who want to know a bit more then “ADS-B = AIRPLANE + GPS + COLOUR DISPLAY = COOL” and may be wondering how GPS with it providing a downlink only is to provide every airplane with other planes’ positions, have a look at the Wikipedia article on the topic. There you’ll find the details!