This bit of news is somewhat fairly recent.

Canonical's Kevin Gunn has issued a status update on new achievements for the Mir Display Server as well as for the next-generation "Unity 8" user-interface.

Among the improvements made to Canonical's Mir Display Server for Ubuntu is Android Ice Cream Sandwich support with HWC 1.0 compliance. Support also landed for surface states and software cursors. Input support is also now fully enabled by default. There's also been LightDM integration work and clean-ups, basic Android/Display logging support, surface improvements, and supported Unity integration on Ir, creating a Unity-Mir layer
[Phoronix] Ubuntu's Mir Moves Ahead With Unity 8 Interface