Ribbon Hero is a game for Word, PowerPoint, and Excel 2007 and 2010, designed to help you boost your Office skills and knowledge
Requirements: Vista or Windows 7 (32/64 bit), Office 2007 or Office 2010 (32/64 bit)
Limitations: English only, Works with Word, Excel, and PowerPoint only, Does not support versions of Office earlier than Office 2007
The new Microsoft Office Fluent UI replaces the previous system of layered menus, toolbars, and task panes with a simpler system optimized for efficiency and discoverability. These add-ins install a Get Started tab to the Office Ribbon. Commands on this tab give you easy access to free content on Office Online that helps you learn Office quickly.
Here is a list of great demos that show you more ways to experience the new user interface.
If you are responsible for Office deployment check out the Fluent User Interface Developer Center. This is a great compilation of whitepapers, videos, and how-to guides.