Well, I guess I'm more concerned about the scenario in which people are for some reason unable to back up their content, or if a person were to max out their authorizations for content. So iTunes give you, what, 5 devices per song? Over a lifetime a person is going to exceed that, without question, especially if you're sporting a desktop and a laptop both.
So my concern is that if I purchase, say, a thousand dollars in music or video over the course of a few years, once I've replaced my computer a few times and possibly lost my backups, will all of my purchases be persistent within my account? If I'm a sixty year old man and I decide I want to listen to the Violent Femmes, am I going to have to dish out another ten bucks for the content?