So yesterday Google rolled out a new GUI for Google Docs and Spreadsheets, and lookee here: The interface looks a lot like Windows Explorer.
On the right of the start page you'll find a navigation pane with folders. That's folders, a marked departure from the tagging taxonomic structure they inherited from Writely after acquiring the company in 2005. The new folder method does allow you to save docs in multiple folders, though, so it's kind of a hybrid approach. My guess: Google is trying to broaden the appeal of the online service to pave the way for including PowerPoint support later this year. Tags appeal to techies, folders appeal to everybody else.
Of course, this begs the question: What about Gmail? Google's e-mail app, with only 4 percent market share, continues to stick to a tags-only taxonomy. I wonder if tags are a bridge too far for layusers, who've grown up on the folder metaphor. Below, a screenshot of the new docs GUI.