Google is steadily moving forward with releases around the Google Cloud Print Platform.
You have been able to print on mobile versions of Google Docs and Gmail, and on Chrome running on Windows since February.
Today they released a Beta version of Google Cloud Print that runs inChrome for MacOS
10.5 and above.
So you can print any HTML, PDF, or any page you are viewing in the Chrome browser running on the Mac to your printer registered with Google Cloud Print.