As you may already know, Canonical maintains the Ubuntu Desktop Next flavor of Ubuntu, an Ubuntu system that uses by default Unity 8 and Mir, the two being used only on Ubuntu Touch for now.
Some experimental Ubuntu Snappy Core Images have been built, but they freeze the login screen, for now.
Also worth mentioning, a Ubuntu Snappy Core Image for Raspberry Pi 2 has been available for a while now, for everybody that owns such an ARM mini-computer.
For those who don’t know yet, Ubuntu Snappy Core is Canonical’s operating system for the internet of things and features snappy packages, which are enhanced click packages that bundle in all the required dependencies.