This excellent, elegant post at minimalmac does a marvelous job of outlining a reality that must be uncomfortable for Microsoft:
No one really needs Microsoft Office.
My company has been mostly an Apple iWork shop for some time now. Pages is our default word processor and, although we do a lot of training presentations, the truly exceptional capabilities of Keynote has kept my copy of PowerPoint gathering dust for some time.
The only exception has been Excel. We do a metric truckload of spreadsheets and graphs, and our invested time into the platform has made it harder to transition out. However, recent experiences with the "upgrade" to Office 2011 for Mac has us looking very closely at completing that transition. It should never take 45 minutes and a web search to figure out how to make a text box... Not to mention the f$@king ribbon!
For many people, for some time, it's been a common refrain that one must have Office to work on a computer. That refrain may no longer ring true.
(Tip of the hat to Daring Fireball for bringing this link to my attention).