I believe that it will be around for quite some time and that the installed base of users will grow tremendously during the next 18 months. Here's the bottom line, though. The VAST majority of musical artists, even those who appear successful, rarely make enough money to live on if any at all. The Net is opening the channel between creator and audience. However, the fact is that even with this new connectivity in place, the VAST majority of artists will still not make money.
Music is art.
Those who invest time and money into their art have to do so with the understanding that it may never be recouped. In general, consumers are willing to pay for art that pleases them. Personally I've purchased many CDs from bands that I first experienced via an MP3 sample song I downloaded. Whoever figures out the question of how an artist can make money while giving away their music will set the direction for the new distribution future. I have found that with high-speed cable and a cd burner, I can do whatever I want with any music I want.