I don't know if that's true, but there's something important the post doesn't address: the potential declining costs of providing online storage. Might the two not balance each other out for the foreseeable future?
I refer to this most excellent post by BackBlaze, which outlines how they do storage: http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-h...
While we might not see many additional leaps of over 90% reduction in cloud storage costs, I (a) wonder how much headroom such innovation bought Backblaze, and (b) whether their main costs, hard drive, will keep pace with user demands.