Google Docs: The New Microsoft Word??

I had never heard of Google Docs before today, and now I can see it seriously affecting the power of Microsoft Office. Google Docs has a clean format, almost all of the same tools available as Microsoft Word, and most importantly IT'S FREE. Anyone who has had to shell out a few hundred dollars for Microsoft Office might check out Google Docs and want to kick themselves. At the same time there are some things that seem to be missing Google Docs. Although the format seems clean, I cannot figure out how to double space my work, I can't tell how it would look prior to printing, and when I choose to 'preview as a webpage' it told me there was an internal error. I do not see Google Docs ever completely taking over the work place or even the home, but I can see it taking revenue away from Microsoft in the future.