Congratulations to Gopro. They basically created the market of action cams. The dinosaurs Sony, Nikon, Canon are seeing their hegemony erode because of the incredible vision and product design of Gopro.
One interesting thing is that we are seeing a huge amount of "fisheye" videos now because of Gopro. Where it was once an extremely gimmicky kind of image, now it is becoming much more normal to see. And in certain situations (surfing, skiing) it really makes sense.