Even if Google could do something like Diaspora at near zero cost, they wouldn't. Their goals are opposite.
Diaspora is meant to be a mean of decentralization, just like Wordpress. Google is a mean of centralization, just like Facebook. Diaspora founders would love to see the ubiquity of Sheeva plugs (or whatever cheap home server we could get). Google would hate it: that would mean the death of most of their online services. Only the fundamentally centralized ones, like search, would be left. Gmail, Blogger, YouTube… would mostly die. (I'm aware of the asymmetric bandwidth issue. But if Sheeva plugs are ubiquitous, bandwidth will be symmetric anyway.)
Diaspora is meant to be a mean of decentralization, just like Wordpress. Google is a mean of centralization, just like Facebook. Diaspora founders would love to see the ubiquity of Sheeva plugs (or whatever cheap home server we could get). Google would hate it: that would mean the death of most of their online services. Only the fundamentally centralized ones, like search, would be left. Gmail, Blogger, YouTube… would mostly die. (I'm aware of the asymmetric bandwidth issue. But if Sheeva plugs are ubiquitous, bandwidth will be symmetric anyway.)