At the Professional Developers Conference today, Bill Gates and company will dribble out more details about Vista, Office 12 and other products. Here's a sample of what Office 12 (Office 2006? or 2007?) Word interface will look like.
For these interface tweaks and more, you'll have to wait another year or more. Why not offer interface improvements now for free or a nominal fee, instead of waiting until all the new functionality pieces fall into place? If the interface legitimately improves user productivity, and the underlying functionality doesn't have to change, make it available as an option--classic and new. Certainly, users and IT organizations don't want to confuse users with new ways to do things every few months, but the Office update cycle, except for patches, is from a bygone era of the software industry. Focus on continuous improvement and let the users decide if they want to apply the new interface skin or plug in other functionality.
Update: I've been watching the PDC Gates keynote and the new Office 12 interface functionality goes far deeper than navigation and discovery in the various applications. It's typical for Microsoft to spend years on a new upgrade, and then try to convince people of the value of the new features, many of which they won't ever use and require updates to Microsoft's server products and Windows. But, the new model for software today is continuous improvement, not big bang costly upgrades that promise "better results, faster" in 18 months or two years. Office is slated to ship in late 2006. Among the 400 million Office users Microsoft claims, the majority haven't even upgraded to the current version, Office 2003. Office 12 will likely be called Office 2007 if Microsoft keeps the same naming conventions. Providing more continuous improvement and creating an better ecosystem of partner plug-ins around Office would make it a better platform for users, not just Microsoft.