Alex,
I agree that Google could somehow gain financially, but as long as they respect the wishes of the copyright holders and they aren't violating copyright law, they should be able to generate revenue somehow by offering the Google Print service.
I am encouraged by two pioneers,
Vint Cerf, the
father of the internet, and
Andy Hertzfeld, an open source advocate, joining the Google team. I do think Google is doing a lot of the things they are for altruistic reasons, but if they can make money while democratizing the internet and "doing no evil", what's the harm?