Apparently, Microsoft is updating the ribbon interface in Office 2007 because people are complaining about the size of the ribbon. Personally, I love the ribbon. My only problem with it is, as an advanced user, it's sometimes harder to find what I need. That'll all come with change, tho. I accept change pretty easily, when it makes sense, and after using the new interface, I have to say that it does make sense. I do know a small group of people that complained about the size of the ribbon, but they did like the idea. I also remember seeing a comment about how the larger size of the icons makes it easier to click on them, which, after taking a second to think about it, does make a lot of sense. I'm a speed clicker, so I can understand this line of thinking. While I've never had an issue with the 16x16 icons, I have to admit that it makes sense.
Also of note, Jensen Harris took a look at the size and compared it to Office 97. While I would've preferred a comparison to Office 2003, it was still a nice perspective.