I never really understood the value proposition of the trendy databases for most businesses. Nearly everyone wants to be a Facebook or Google size entity (or thinks they do), but the fact is most businesses who attempt to build in scale like that are wasting their time and money.
They are building too much infrastructure instead of revenue generating product, in hopes that they someday need it. Kind of like buying an 18-wheel over the road truck when a pickup will meet your current needs just fine.
I think it is a good thing Google is looking back at SQL based systems, I believe it will be beneficial, especially for startups who want, even need, to be on the technological edge, but are vulnerable to falling over the edge by building too big.