One of the cool new features in Office 2010 is the BackStage view, which replaces the old File menu with a full screen interface. Here's the info from my Office 2010 Special Report:
Office 2010 replaces the old File menu with a new interface called Backstage. This view, which is triggered by clicking the application button, takes up the entire application window and represents the "behind the scenes operations that you can perform on the currently loaded document." It's also the place where you can access application options and other items that were previously found in the File menu, including Print, another essential, or core, Office capability. (In Backstage parlance, the document content is considered "on stage.")