You still can't get the music off that iPod without some 3rd party software anyway, so its just as "secure" as what Apple is doing now.
Plus it requires two iPods, one being a small shuffle, and an extra piece of hardware. It's not like people will just run into each other and duplicate libraries on the fly. You have to plan it which is why it would work well for trips and the like. You could take your whole library with you but still use the shuffle when you're out running around.