The merge proposal hasn't been approved yet, but since it was proposed by Christopher Townsend, Software Engineer at Canonical, it will most probably be merged and available in Ubuntu 14.04 Trusty Tahr.
This branch adds the ability to minimize a single window when clicking on the Unity Launcher icon of that application, a much requested option that was rejected multiple times, even by Mark Shuttleworth... until now, it seems.
This option will be turned off by default, but users will be able to enable it via CCSM (CompizConfig Settings Manager).
