I have listened to pretty much all of the announced songs and there are at least 1-2 dozen that I will buy they day they come out. In my mind well-known does not always equal good music and unknown does not equal bad music.
Of course I would like to see all sizes of bands use this service and I am sure with time they will. Bands and more specifically labels will see this as a viable outlet for exposure and money, but I do not expect them to make public announcements or come to a forum to announce that they are looking at it or working on it.
Anyway I love the way the RBN is shaping up.