Blue Coat just released a new plug-in for classifying iCloud traffic. The plug-in is for PacketWise 8.7.x versions only. (A separate plug-in is available for v9.1.x.)
Download the iCloud plug-in from the Blue Touch Online website:
This plug-in identifies data that is being synched from devices (iPhones, iPads, computers) on the network to the Apple iCloud service and classifies it as iCloud.
See readme for the iCloud plug-in.