Backup to the cloud maybe but I think usage will be limited. However what will be big is moving the datacenter to the cloud. That is already being done and many more are planning it. Then the question is if there is the need to backup that data that is in the cloud or just totally rely on the provider. For example Netflix has moved its datacenter to the cloud. Now the cloud does not have to be Amazon or some other provider. I spoken to a number of clients there are keeping it all inhouse but still moving away from the traditional datacenter configuration to a cloud configuration and for global companies it makes a lot of sense. For smaller companies it makes more sense to use a provider. In either case there is still a need for backup in most cases. Sure the provider may keep the data safe but will they provide a historical archive of the critical data. For that and other reasons such as regulatory and leagel concerns I see backup of data in the cloud as a necessity.