A designer has changed an Ubuntu desktop to make it look like the Metro interface used by Microsoft in Windows 8.1, and the result is actually not that bad.
Just like Ubuntu's Unity, the Metro interface has not been well received by the community, and a large part of the user base downright hates it. A developer even managed to make a total transformation pack to change its look from Metro look to Ubuntu.
A designer (TheTechnoToast) on DeviantArt has made a design to show what Ubuntu would look like with a Metro interface. It's true, it uses the latest LTS version as a base, but Unity has changed little since then.
Entitled Ubuntu 12.04 Metro Style, this is just a concept which will probably never see fruition, but it's interesting to observe that it's not looking all that bad.