The Foundation's ODF Plugin permits users or administrators to set MS Word to default to the ISO OpenDocument Format (.odt).
Fig. 1: (Word 2003) Under Tools -> Options, Save tab in Word, you can change the default to .odt as if it were native to the application.
This permits individuals & organizations to configure their PCs to open, save and work primarily in the ISO OpenDocument Format.
Once the organization has safely acclimatized to working and archiving in ODF, the next step toward vendor-neutrality would necessarily require a good look at the business processes touching the desktop -- both the formal and lighter-weight, improvised or ad hoc business processes through which people get things done.