As of current precise, it appears behavior has changed, but still is inconsistent.
In Unity3D there are launchers on both displays. In Unity2D there is just one (on the left-most display).
As per the multi-monitor specification, the bug is with Unity2D:
"""
2.8. Launcher
The Launcher is now available on all displays. Each Launcher contains the same set of application icons, showing both pinned and running applications.
"""
As of current precise, it appears behavior has changed, but still is inconsistent.
In Unity3D there are launchers on both displays. In Unity2D there is just one (on the left-most display).
As per the multi-monitor specification, the bug is with Unity2D:
"""
2.8. Launcher
The Launcher is now available on all displays. Each Launcher contains the same set of application icons, showing both pinned and running applications.
"""