The P2P thing is about listening without charge.
For me in most cases, I just need a few good samples to be convinced that I will like the CD. And thus far, I have been very impressed with the iTunes store. It has major albums, and allows 30 second previews of any song without ever giving them any information. I doubt I will buy music off the iTunes system, but I will use it to get a preview and shop online elsewhere to have a CD sent to my house.
On the whole issue, I'll probably think up a response later.