I use Google Docs fairly often. The template gallery is nothing less than incredible (and money-saving in many ways). I also maintain at least 5 legacy accounts that I intend on using more often later this year.
This morning, I opened a doc from one of those accounts. Nothing looked new?
According to the Google Docs info page, the new version should be the default:
So far I haven't found any downside to the newer version but you might want to check and see which one you're using. The HTML editing and shortcuts, at least for me, are a win.
PS: You might also want to check out the recently released Collaborative Drawing Editor while you're there as well as the new Google Docs sharing features announced this past Friday.