I think you will either "lease" an album online, like on demand movies, or buy it and either have lifetime download privliges to listen to it, or else be able to download it onto a harddrive. Eventually, a digital tracer could be imbedded into copies to leave a trail back to the original purchaser.
I have read articles about how the album is becoming an endangered species because of music download websites. People buy only the songs they want instead of buying 12-14 songs at a time on an album just to get the couple of tunes that they really want. But we older folks will always likely maintain a market for traditional albums because that is the paradigm we are comfortable with.