Comment 49 for bug 733349

This bug needs to be changed back to "Unity launcher buttons should allow to minimize apps, not just
 launch/restore"

Here's why: https://lists.launchpad.net/ayatana/msg05594.html

The launcher follows an app-centric paradigm like OS X and the "dock". I doubt a lot of thought went into this when designing Unity (judging by the lack of replies) but this is not for here. Now that we are stuck with this OS X like app-centric interface let's look at what their Dock is doing:

There's a hide option in the context right-click/long-click menu, this functionality is expected by people using app-centric as well as window-centric interfaces. Adding it to the Launcher will come at absolutely no cost in terms of usability as far as I can see.

Like in OS X other useful option could be put there as well: force quit, hide others, open at login. Visual separator avoid clutter and some options are hidden by default and only toggled when pressing the alt key.

Screenshot of a Dock menu: http://i.imgur.com/z5Aw6.jpg