David Coursey makes an interesting point on why many people are not interested in Office competitors WordPerfect and StarOffice (OpenOffice). Outlook makes the Office Suite invaluable to a lot of people. Neither package offers and email client. I know on Linux you have Evolution, but it does not come with OpenOffice. Why should someone who has Office, which comes bundled with an email client have to install OO and then install another program?

I think the only thing saving Microsoft right now on the Office side is Exchange Server. Outlook integrates so well with it (I don’t know if I am joking or being serious) that finding a quality replacement can be difficult.