The WordPress admin seems to be a hot topic for a wide range of people. Personally I've always been of the side that I really like the admin, find it easy to use (especially in comparison with other CMSs), and think it does a good job in facilitating the work you're trying to get done. Many people feel it could be improved though and a good percentage have taken the time to develop discussions, resources, and even functional plugins to implement their ideas.
The focus of this piece in particular lands on CSS preprocessors being the solution. I think that's interesting, but even with a CSS preprocessor the preprocessed stylesheets would need to be put together just right to allow for complete and utter customization top to bottom. There's an interesting comment thread at the bottom of the article that's worth reading.