EMC unit Isilon Systems have had a decent order from Apple, 12 petabytes worth of data storage to be used for the iTunes cloud. This large order might be made for the construction of Apple's huge data center in Maiden, North Carolina. The new building is expected to be the hub for a new version of iTunes which relies on storing media in the cloud, which is set to replace the old method of the data being stored on customers HDDs.
The main focus of the cloud will be for storing video content, rather than music which is why so much storage is required. Rumors have been flying around for quite some time that Apple would be following in the footsteps of Google and Amazon with the content they purchased being accessed from a centralized server. This would go hand in hand with that and Apple would have its own digital locker for cloud-based storage of media and content.