I created this page this week :
I am curious about what developers think about the option in Excel 2010 to change contextmenus with RibbonX. Creating a dynamic menu in the Cell menu in Excel 2010 for example is easy to do because every time you right click on a cell it will run the getContent callback so it is very easy to change the menu.
Check out the three examples workbooks that you can download on that page for Excel 2010.
Ron de Bruin