While Steve has valid points, I think he exaggerates and underestimates respectively for the popularity of downloadable/streaming for high quality video and the footprint of blu ray. Big name movies like Avatar and The Dark Knight sold MILLIONS of copies within a week of release on blu ray. By comparison, SACD and DVD-A aren't even known as a format by most consumers. It's a law of diminishing returns. Only audiophiles can/will distinguish between 256kbps CDs and the higher quality formats. That is not the case for Blu Ray.
Meanwhile, itunes still only has 720p whereas the HD standard is 1080p. Even microsoft and sony have got around to delivering 1080p to their consoles. Storage is not to the level where people can comfortably store 1080p collections locally. This will likely continue to be the case, as maximum storage capacities increase, so will the media movies are stored on so as to make it impractical to store collections of 10 to 100s of movies on a disk or SSD, as it may be.
If you go back and read what he says, he is telling you the future of this kind of media is not going to be local storage. Steve is right on this. The content providers don't want people to have their own copies of stuff to keep. So ultimately that is not what will happen. Everything will be streamable, but it will not be able to be archived, thus the end user will have no worries about trying to store a big library of tv and movies on their own.
As much as I believe the major content purveyors are greedy bastages, at the end of the day it is their content, and I agree with their right to do what they wish with their content.
Sure some of the licensing will allow you unlimited or lifetime access ala buying a movie on Amazon Download, but the future is going to be much more contained and closed, and people owning and storing their own copies is not going to be how things work, via streaming or specific media like blu-ray.