Not very fancy I know... But I think that was a very bold move from the editor, away of at least a decade of toolbars. I think this is kind of interesting in terms of usability and might end up being the industry standard in a few years. The Office 2008 for Mac, although not adorning the ribbon, actually does pretty much the same in its toolbox. Selected Tool areas depend on what the user is doing.
A small technical note : This is a fake demo. The video was knocked up using slides on a Powerpoint presentation and each slide shows a different area of the ribbon. The images were found on the www. Now you know.