I'm all for improving the functionality of Wikipedia (e.g., the visual editor and Flow), but I'm very much against changing the look of the site. Wikipedia's layout is simple and puts focus on the content instead of the design.
That's the purpose of good design. Design has but one purpose, to serve the UX. That's it. Anything else is just vanity.
When there's an obvious focus on "design", then the UX is harmed. I put design in quotes because we all know what I'm talking about, design that is more about artistry than utility. Real design is much different from art. While great design can be artistic, design is all about purpose and not that nebulous "What's the purpose of art" type of purpose, but actual utility. Getting something done. Solving a problem.
The Drudge Report is considered by many on the internets to be a terrible "design" yet it's exceptionally well designed for what it does: it allows people to get a very fast listing of headlines curated by someone with a specific point of view. The purpose is precisely clear -- it's a place to browse headlines and perhaps visit links. Going to the Yahoo page, by contrast, I'm left wondering what the heck the purpose of yahoo is. Presumably, it's a news homepage, but it's incredible badly designed because the purpose of the page isn't really clear. It looks like Yahoo hired rejected Naver (http://www.naver.com/) designers and told them to ruin the Yahoo homepage as much as possible while maximizing ad pixels.
Anyway, I know I'm rambling a bit, but I think the "look" of wikipedia could be improved slightly, but the design (at least on the consumer facing (not the editor) side is effective. I especially appreciate the mobile version of Wikipedia. It's a constant companion while I'm out and about and it's fast, crisp and gets me the information I need.
I think you've hit the nail on the head here - there's an enormous amount of pure visual-design influence in UIs these days, prioritizing aesthetics over usability. We can see it in this proposed Wikipedia redesign, in Microsoft's Windows UI overhauls, and in plenty of other websites.
There are major problems with what we see in the 'Athena' screenshots. Why are the navigational controls at the top of the page - ones that expose functionality applicable to the entire site, not the current article - skinned with a photograph taken from the current article? What does a picture of the Beatles convey regarding how to find information on Wikipedia?
The author says that the Athena skin "emphasizes content", but it causes article content to bleed through somewhat into the functional UI, compromising both. This isn't a good thing.
