TG Daily reports about what they saw of Office 2007 at TechEd 2006:
The new model for extensibility in Microsoft Office 2007 is the .NET Framework. Functions written in a .NET language such as C# can be built by Visual Studio 2005 (whether the same extensibility features are included with the Express versions that Microsoft now distributes for free, is yet to be determined). In the completely revised Office 2007, the ribbon is the new container for functions and commands that used to be found on the menu bar, which has become so-o last year..
Check it out over here.