I'm not saying that Google is untrustworthy but with the way they've been acting the past few years the idea of giving them my files feels a bit creepy.

Eric Schmidt: If you have something that you don’t want anyone to know, maybe you shouldn’t be doing it in the first place.

Edited to add: I think it is preferable to spread information among service providers rather than concentrate it in one provider's hands. Google already has my search and email information. I do not think it advisable to add information from files to that.