My understanding is that the users will not be able to plug in their iPad but they can log in with their own apple id and get any apps that they want, barring any restrictions placed on them.
As for music or pictures they could use dropbox to put those on the device. I dont really see much of a use for users of iPads that they do not own to plug them into a computer.
You can only sync music and photos this via the computer that supervised the devices in the first place.
Users can still get apps over the air by logging into their own Apple ID and downloading apps wirelessly. They can get music and photos via other methods (Websites, Dropbox, WebDav, etc) They just can't plug in via USB and do this.