Crossover Office 
Downloaded a trial of Crossover Office, decided to give it a whirl. Know what? So far, it works great with Office 2000 Professional SR-1. It even claims to support the Office XP that we have through work. It doesn't support Office 2003 yet, that's described as "coming soon", "could be a couple of months". Tomorrow I'll load Office XP and the Visio-2000 I have at work and give that a whirl.
Could very well be worth the US$40 it will cost to license.