Then I guess I'm not understanding something.
I see games like Little Big Planet and I believe ModNation Racers will work in a similar way with large amounts of downloadable user made content available to download, and that content IS NOT on the playstation store (except for the ones you do have to pay for like the metal gear solid pack). I could go in right now, publish a level and you could download and play it right away.
So I think to myself, why can't RBN do that? The only answer I can see is that they need compensation for the artists ... is there another answer I'm missing?