This weekend Unity 8 was pushed into the Ubuntu Touch platform for tablets and smart-phones with lots of fixes plus unity-notifications and new stacks for the indicators, settings, webcred, phone, ubuntu-keyboard, and other items. When pushing in Unity 8, developers discovered there was a desktop bug causing the desktop to constantly consume 50% of the CPU resources, but it's since been addressed.
With Unity 8 and the other code tested and landed, Canonical is hoping that before the end of today they will be able to work on some input fixes for Mir and get the display server in Ubuntu Touch to replace Android's SurfaceFlinger.
The latest developments on this matter were shared via the Ubuntu-Phone mailing list. In case you missed it, Mir will not be enabled by default for the Ubuntu 13.10 desktop as there's a number of problems but only the mobile/touch platforms are using the X.Org Server and Wayland alternative. Mir is currently up to version 0.0.13. Unity 7 is also the default desktop of Ubuntu 13.10 for non-Touch platforms.