Having recently rolled out 2007 in the company I work for, I have had to try learn 2007 very quickly. While I am still no advanced user yet, I know these issues have come up:
How about some mention of the Paragraph line spacing defaults in 2007. I know the first time I used 2007, that threw me off a bit.
Also maybe some mention of the incompatibilities when creating a document with the intention of saving it in 2003 format and using the compatibility checker function.
Last thing is the way the menu adapts depending on what function you are using and the way that it will only be visible at the stage you edit that function. eg: tables and the ribbon menu's that pop up when needed. If you havent noticed create a table and when done, you will see the 2 extra menus that pop up
Just some thought