I agree that all of the Google X projects of today will ultimately be what defines Google tomorrow. The fact that they have the guts to tackle projects that are incredibly risky for a business but meaningful for humanity is a major reason I'm happy to use their products. I love the geek factor.
I'm not sure it's that risky for them. Google tends to try a bunch of different stuff, but doesn't seem too shy about cuttings its losses and failing reasonably fast when needed.
