Too bad it won't happen for the last reason you mentioned. I'll use the systems to figure out what I want, but in the end, I'm slapping my ten bucks down for a CD if I like the music for several reasons: one, I feel the need to support the artist making the music. Two, I hate the idea of poor quality MP3s. As a bonus, I love the packaging and reading material (most of my new purchases have gone toward establishing a jazz collection and they prove very valuable to me education-wise).
If they distributed online, it would have to be in the form of .wav files. And most people can't accomodate that. So for now, I treat it like a library. I listen and I get rid of it if I don't like it (just wasting space). What I do like, I try to buy.
If you're interested in getting good-quality music for free, check out
FurthurNet, a client for sharing lossless music from bands that have tolerant live-taping policies. It's legal, and they use a compressed format that doesn't sacrifice any sound quality (called .shn, or shorten). Pretty neat stuff. I've found lots of interesting music so far. The majority of the collections are Greatful Dead and other jam bands, since that's where the taping trend took off, but there's a wide range of artists and genres. A lot of the recordings are direct to digital off the soundboards, so they sound great. [I am in no way affiliated. Just happy.]
I also try to support artist-friendly labels like Robert Fripp's
DGM, but they're in somewhat of a reconfiguration right now, so I'm not sure what's going on there.
Anyhow, just thought I'd throw two more cents out there.