The new Microsoft Office versions have new default fonts:
The default font may be changed if desired by following the steps below.
Note: The default font applies to new documents based on the active template (template: A file or files that contain the structure and tools for shaping such elements as the style and page layout of finished files. For example, Word templates can shape a single document, and FrontPage templates can shape an entire Web site.). Different templates might use different default font settings.