It is certainly worth mentioning that a large number of Mac users actively boycott Microsoft products, eschewing Internet Explorer, Office, and Outlook Express in favor of the many capable alternatives. This is by no means a majority, but as more alternatives become available there is no compelling reason to choose MS over others.
And it may be said that MS shoots itself in the foot once in awhile, as Apple was wont to do back in its "Not Invented Here" heyday. For example, the MS Office spell-checker and dictionary is separate from the system-wide dictionary and spellchecker, and when Jaguar is released I'll bet it will be many months - if ever - before Entourage makes use of the system-wide Address Book.
Of course, any developer is free to add support for the new facilities of Mac OS X, so it becomes ever-harder for MS products to differentiate themselves. And if they decide to follow their usual tactic of leveraging Office's unique file formats to try to push users into adopting it will certainly backfire.
In order for Microsoft Office to become more successful they're going to need to price it competitively (i.e., in accord with market realities) and continue to improve and streamline it. I have Word v.X at work and I find it quite a pleasure to use. But since I only ever use its basic features it's just not worth the price they're charging for me to upgrade my personal copy.
