Update 3/11/2006: Now On-line http://office.microsoft.com/en-us/FX100647101033.aspx?pid=CL100569831033 (no more beta...) Not only looks very cool, but also has lots of new content that get you up to speed with the new version quickly. Don't forget we've got free courses on Office 2007 on the e-learning site. Just search for Office 2007 there and you'll find a whole bunch of free courses that do a good job at introducing you to the new UI and Features.
You can tell we are close to launch date, even the Office On-line Site has a 2007 look and feel: http://officebeta.iponet.net/en-us/sharepointserver/FX100492001033.aspx
While you are there be sure to check out the Additional Resources (Bottom Left on page) with links to (now free!) e-learning courses on Microsoft Office System 2007 for developers and users.