I think this is an overall brilliant move. MySpace has created an audience that's craving new music, and Snocap's finally got a business model and a niche that it can use to succeed.
However, I want to raise a note of caution, especially to musicians that have started up in the last 3-5 years. If you're new to this, you might not realize that a company called MP3.com tried this same strategy during the tech bubble. Not only did they let artists sell music, they even split ad revenues with folks that posted the most-visited pages.
It wasn't the dot-com burst that brought MP3.com down -- it was a buyout by a major label that wanted those eyeballs on its own projects. In the meantime, an entire ecosystem had grown up around MP3.com -- folks even quit their jobs to become virtual promoters and virtual managers. After MP3.com shut down (it was later purchased and re-imagined by the folks at CNet), a lot of people got so disillusioned that they stopped making music altogether.
Why signal such a cautionary note after such good news? Selling music to your fans through MySpace should be just one of your revenue streams. The most effective musicians use MySpace as a funnel into their own websites, street teams, and shopping carts. The sooner you can move folks off of any external platform and into your own database, the better you'll be in the long term. That way, if any one platform disappears overnight (like MP3.com did), you'll still have other ways to get support from your audience.