First a correction: technically, these mockups don't follow the Metro design guidelines to the letter - there's definitely a lot of the Zune application in there. Still, what you're looking at is the more traditional Windows desktop, in a more Metro-ish design. The way I see it, this mockup (or something similar) is a far better alternative next to the touch Metro interface than the old-fashioned Aero desktop Microsoft will include instead.
"This is a desktop concept that I've recently put together for fun," Sputnik8 writes, "I thought I'd post a few screens to see what people here think. The screens include variations of explorer, IE (with a quick redesign of windows.com and Bing), media center/player, and Skype. Note that I didn't aim for the design to be completely consistent with what MS calls 'Metro' (for instance, I specifically didn't want loops around icons, among other things)."
I've articulated my concerns about Metro on the desktop before. The most pressing issue is that while lobotomising window management may make sense on tablets and other relatively small touch screen devices, it doesn't make sense on regular devices with larger screens and mouse and keyboard. I need to get work done, and in Metro, I cannot. Sure, there's a legacy desktop now, but as the word legacy implies, it has no future.
I like Microsoft's approach of unifying devices - why not use a tablet as a regular PC when docked - but trying to shove a limiting tablet interface down my throat is not the way to get there. I'd much rather switch between something like this mockup when using the device as a regular PC, and Metro-proper when using it as a tablet.
Microsoft's developer tools are designed so that you can create multiple different user interfaces for the same application, so this should not be a hard thing to do. You're already supposed to deliver both a full-screen and a 1/4 screen interface for Metro anyway - why not add a full desktop interface as well?
It's probably too late for Windows 8 (unless Microsoft has something up its sleeve come MWC), but they should hire this man or woman. Failing that - Gtk+ and Qt themers, work your magic!