well there is the way that the cable companies and content owners pick and chose what shows to offer on-demand and for how long. as long as they do that then the end user need to be able to record the show so that they can view it when they want and not have it pulled off the cloud by the cable and content folks.
True, as of today. But I suspect you'll see more and more content moving into the realms of on-demand and customers can have the ability to "record" that without having to worry about two or more things possibly overlapping. You can already do this to some extent in the UK with Sky's Anytime+ service. The obvious next step is to simply replace the "record" button in the cable/satelitte box with a background download from the t'interwebs.