That's an interesting point. I suspect it depends a lot upon their concrete programming skills as demonstrated in the interview. It's funny how my first reaction - even as someone who always says "Your degree doesn't define you, and talent will find jobs no matter where you went to school" - was to assume that the Stanford history major is much smarter than the CSU Chico CS major, and just happened to pick the wrong major. But that's not necessarily true: maybe the guy from Chico is a Zawinski-class programming genius that happened to grow up in a family with no money and no college expectations. The point of the interview is to tease out circumstances like that so talented people from bad situations can rise to the top anyway.
It's also interesting because I know some Amherst history majors that I could never imagine getting a job at Google. But I also know an Amherst Asian Languages & Civ major who does work at Google, albeit in a non-technical position. Yet I don't know anyone at Google from a CSU: my friends here are from Rice/Brown/Brown/Amherst/Stanford/Berkeley/ Stanford/UChic/Cornell/Berkeley/Berkeley/ CMU/Duke/UCSD.