Really hard to say apart from it's the masses that lead the market. The reason there aren't many high quality download sites with substantial libraries is because the infrastructure isn't there to handle mass downloads. That is the future for the next while though, once the average consumer demands higher quality recordings...
Further down the line though during the next decade it's hard to say but my personal opinion is that we will see substantial changes in interface structure and information options (to replace the ever important artwork and sleeves) and the ability to listen to any song ever made, instantly from the comfort of your padded chair.
An avid turntable fan myself, it will go the same way Kodachrome has gone recently. Let's hope it's not too soon.
