Referring to the Microsoft Office System that shipped in October of last year, this article from E-Commerce Times is a short and interesting read.  It captures some of the vision around the Office System within Microsoft. 

I especially like this BillG quote:

"Office defines business productivity," Bill Gates, Microsoft's chairman, told financial analysts in July. "The productivity area is probably the most important franchise that we have."

http://www.ecommercetimes.com/story/35988.html