Most people are getting aware of the new upcoming version of Office. There are already several resources available and I thought I'd list some:

Some videos: Channel 9 In the office
Some report by Forrester: Developers get ready for 2007 Office system
A quick introduction to the new UI of 2007 Office System: First look 2007 Office System
extension code samples, supplemental developer white papers: 2007 Office System Starter Kit: Enterprise Content Management Starter Kit

Grz, Kris.