You are right a world wide audience is what is needed for any serious player in music distribution to truly be successful and I do think that only time will tell. But I think because it is Google and their goal is to be a major player in ALL media it is going to be hard for it to fail and even harder for us on the outside looking in to see it if it does. Meaning Google is so big now that they can force feed this product down our throats through endless ads and promotions that we will believe we need it. Even if the numbers are showing that it is failing I don't see them pulling the plug on it. Remember they brought You Tube even when it wasn't really making money, but they believed they could find a way that it could. I have read that both Larry and Sergey are behind this idea so I think there will be endless tweaking until they get it right or run out of money..lol.
Anyway, like your site. Good concept with building a community aspects. Good stuff!