So far it can't be synced; you have to make a backup and load that backup onto your other devices. There are a few threads here discussing that; I've done it by email and by file transfer. Both work well. Actual sync would be nice, but it doesn't sound easy to achieve. I just make sure to always make my edits on the iPad, so it always has the newest version of the song list. Then, every now and then I update the other devices to what the iPad has.