On November 4 Mark Shuttleworth announced that Unity will switch from using X to using the Wayland display server.
Wayland is a display server relying on DRM (Direct Rendering Manager), GEM (Graphics Execution Manager) and KMS (kernel mode-setting) for rendering. This allows Wayland to stay lightweight and provide lag and tear free rendering.
Wayland is currently not stable enough for everyday use and Mark Shuttleworth said that it will probably take a year or so before we’ll see something useful.
The fact that Wayland relies on DRM, GEM and KMS for rendering shuts out the proprietary drivers from being used. This might become a problem for some users since some of the open source drivers lacks supports for the latest hardware and sometimes, when there is support, the experience isn’t all that stable.
The need for DRM, GEM, and KMS also leaves out some older hardware that doesn’t support one or more of the above.
Another thing that might pose a problem for older hardware is that Wayland uses OpenGL and OpenGL ES for compositing.
So where Wayland may be revolutionary and lightweight, it may draw a line in the sand separating the old hardware from the new.