Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A306 Safari/6531.22.7)
No, but there are other social networks apps that are not tied to purchasing music yet are used for that at the same time. I don't see Ping as having legs.
I'd use it if there was a single artist on my playlists that was signed up for Ping. I guess it's not really cool for death and metal core bands to sign up for Ping... not yet anyway.