After Twitter integration and iPad migration, looks like the next stop for Ping is social playlists. That's right -- the next time you make a mix in iTunes 10, clicking on the playlist arrow will give you two options: you can either purchase the playlist as a gift to your friend or loved one, or publish the playlist to Ping itself. Once your playlist is published, you can even give your friends on the network the option to edit it, making it a community playlist of sorts. Of course, this last option only works if you
