1) The only music available via the cloud are songs you've purchased. You have to sign in to get access to the music and only songs purchased with the account are available. Possible, but I doubt anyone would really use it if this was the case. 2) You are able to upload any music that you haven't purchased and add it to your cloud account. I think this is most likely but doesn't really differentiate it from current competitors. 3) Any music that you have in your itunes is instantly available online. I highly doubt this will be the case.
Anyone else have any thoughts on how it would work? Would you use it if you can't get pirated music on the cloud?