Yes! now you can make your Firefox browser look like any program of Microsoft Office 2010. Microsoft Office 2010 has a very sleek and stylish interface. The good thing with this Firefox theme is that it has got the ability to skin Firefox like almost all programs included in Office 2010 suite.
This Office 2010 theme for Firefox is called TwentyTen theme. The theme can be downloaded from Firefox addons page. To activate/deactivate the theme, go to Firefox -> Tools -> Addons -> Themes.