The official statement:
Well I'm glad the search engine company I use every day got that right.
The Prop. 8 argument is between a fraction of the public who think they need to impose their moral postures on society in order to protect themselves from personal and social impurity -- and another (hopefully larger) fraction that thinks legalizing same-sex marriage is a matter of elementary fairness, of civil equality.
That Google and other monster corporations might place themselves on the side of civil rights is not surprising. Large, impersonal corporate entities thrive in defined legal environments in which prejudices and passions are constrained by law, though they are not always so good on equity for the low end of their workforces.
In general, they have supported affirmative action policies that create anxiety of about possible unfair outcomes in white populations. The upside of having clear rules that promote inclusion outweighs the downside of the anxieties of some (mostly) white men.
Many of the big guys, including banks, clothing maker Levi Strauss, and the power company, PG&E, have long been supportive of normalizing the legal status of gay people. For them, it's simply good business. And having a reputation for tolerance probably offers a competitive advantage in recruiting a young, creative workforce.
The culture of people who support something like Prop. 8 barely intersects with that of the No folks. I'll be writing more about this in a few days, but if you want a look at what moves the folks who feel threatened by same-sex marriage, try Chris Hedges' American Fascists: The Christian Right and the War on America. The link is to a Google book, by the way. It's everywhere, that Google.