The cloud printing service was announced a few months ago as part of its web-centric operating systemís capabilities, so the update to Docs makes sense if Google wants to make Chrome OS + Docs a better rival to Microsoft's Windows and Office, for example. Basically Google is doing away with the need of locally stored drivers by keeping them on their servers and simply sending the print job to the appropriate printer.
For it to work, users will have to install a small proxy software on their computer that will communicate with a printer attached to it or thatís on the same network. This means the computer has to be turned on and connected to the Internet for the print service to work, but Google hopes printer manufacturers will eventually make their printers "cloud aware" from the beginning.
Other features expected to hit Google Docs soon include support for third party applications and a device sync function. Although no official announcement has been made, the folks at Google Operating System blog speculate that the first probably describes APIs that could be used to extend Docs beyond its current capabilities (by enabling PDF editing, for example), while device sync could push Docs files to a number of devices (much like Google calendar and contacts with Android) allowing users to make changes on any of them and automatically re-sync them to the Docs service.