The following resource covers the changes in most of the products within the 2007 Office System.  It may be useful for discussions with customers that are trying to determine what features have been added, removed, or changed within the Office 2007 apps.

 

http://technet2.microsoft.com/Office/en-us/library/a9189734-e303-4d7d-93eb-3584c358d1c91033.mspx?mfr=true