I like the idea, Joe but it's just not feasible.
Recording a video is one thing. Creating an interactive demo is another. 1 takes a few minutes of scripting and then a few minutes of recording. The other requires the packaging of art assets, game code, game engine and an executable into a downloadable file. The video can be streamed from online servers (or downloaded for a few MB's) while the other requires possibly a few hundred MB's to be downloaded.
Even the 3DS videos are not the same thing as the interactive demos seen at E3 2010.
Gumby_Trucker,mentioned a way to pan and scan a video to give a similar look at the demos but you'd get distorted perspectives if it tried to work like an in game camera....as is done in those real time demos.
The rEVOLution is not being televised
