This is where I seriously wonder about the "cloud". Bouncing a print job over my (relatively) slow internet uplink, then back down my internet connection, then to my printer? As an option this is nifty, as the only way of printing it sucks. Printing locally is already pretty easy. All this just so we can slap the "CLOUD! CLOOOOOOOUUD!" imprimatur on it?
I also wonder about the security implications. And it is not just the stealing of data. A government man in the middle can censor the printing of material he finds offensive, subpoena Google, and arrest the person attempting to print it.
I think the idea is you won't bounce a job from your computer, up to google, then back to your printer - instead, google will generate the job directly, then the printer will download it from google and print.