My guess is that the future of video is split. On the one hand you'll have collectors and videophiles who will continue to buy physical media for its superior quality (both in terms of picture quality and in terms of available extras like commentaries, extra documentaries and other stuff not usually found in online releases) and so that they'll have stuff to show off on their shelves. This will probably be a fairly small bit of the market, sort of like Laserdisc was, but it will probably be better stocked with titles as production costs for BluRay discs (and probably whatever will come next after them) are much lower than LD production costs were. On the other hand, the "normal" people who just want to watch their movies and TV reruns and who don't care much about picture quality once it gets to the "good enough" stage will move to streaming and digital downloads.