Microsoft Office Interactive Developer Map v.2
Something to check out if you haven't seen it yet. This was released earlier this year.
The Microsoft Office Interactive Developer Map is a Windows Presentation Foundation (WPF) application that helps developers visualize the different programs, servers, services, and tools that will help them build solutions. It allows them to drill down to each product and technology and learn about new features, objects, Web services, namespaces, and schemas required to extend Microsoft Office and build custom Office Business Applications (OBAs). This application also includes links and pointers to online resources available on Office Online, MSDN, TechNet, Channel 9, Channel 10, and OBA Central.