I highly highly doubt that this is an actual appeal by them to change the MediaWiki interface. I see this purely as a publicity stunt / marketing move, intended to get their brand and abilities out there in front of people. And to be frank, I think they're being quite successful at that. UX/practicality aside, most of the components do look good. (though good parts of it remind me of Google, Quora, and other prominent sites)
(Seeing this site reminded me of the guy who did the Windows redesign work a few months ago, which means that the windows redesign guy did a good job marketing/branding himself too!)
One of the absolute biggest challenges in hiring a web design firm is getting them to understand the company and work within the real constraints of the business and budget. Pie-in-the-sky projects like this one don't demonstrate that the firm can do that.
They seem to be very effective and successful, until you see their incapability of grasping their advised Wiki logo's and Wordpress logos similarity. That's where they just fail.
(Seeing this site reminded me of the guy who did the Windows redesign work a few months ago, which means that the windows redesign guy did a good job marketing/branding himself too!)