I like your approach, but I think you are looking at a problem of remote server backup software consolidation. This stems mainly from the fact that on large numbers of sources of backup (think students in a campus or road warriors in a company), having all resources in one place comes cheaper and greener (especially with today's trends in storage virtualization), as long as you consider the cost and convenience of using broadband for backup acceptable. While local backup can definitely do some jobs well, it will not insure the same safeguarding of the data as backup to remote server does. So the conclusion is simple - more users sharing their backup infrastructure is more effective cost-wise and energy-wise as well.