To try it yourself, you'll need to own a Chromebook or Chromebox. Make sure you're on the dev channel, with version 29.0.1547.2 or later. (Note that the dev channel is considered "unstable," so odd things could happen if you use it. Then type in "about://flags" (no quotes) into the URL line, which should bring up a long list of options. "Enable document editing" will allow you to edit the documents after a quick restart.
Eventually, these changes should come to the main (stable) channel of Chrome, meaning that most users will be able to natively edit Office documents. At that point, if Google increases QuickOffice's capabilities, look out.
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