The Story of the Office Ribbon
I came across this great presentation about the evolution of the Office 2007 Ribbon. While I'm not personally much of a fan of the ribbon, the development process was really interesting to listen to. I found the story of "feature creep" up to Office 2003 to be a really good example of what to avoid in revisions of a product.
One portion which I found interesting was where he showed various solutions they had to deal with placing the thousands of commands within the simpler, reorganized design. There was one where they would switch the entire display of the application to reflect the current task. For example, picture task would invoke a unique ribbon with all of the formatting options for a picture. This seemed really good, until they applied it to tables. With tables, each cell can contain text, other tables, images, and so on. As soon as you used a table, you were back at square one! This was an especially difficult process with foreign languages where you commonly write text exclusively in tables.
I'd highly recommend anyone with an interest in HCI listen to this presentation.