I just saw this announced on the kicad.info forums... Sweet!
https://github.com/xesscorp/HierPlaceTo install it on OS X. Unfortunately, the way KiCAD is currently bundled it needs to be reinstalled whenever KiCAD is upgraded.
git clone git@github.com:xesscorp/HierPlace.git
cd HierPlace
sudo cp HierPlace.py /Applications/Kicad/kicad.app/Contents/SharedSupport/scripting/plugins
sudo chown $LOGNAME:admin /Applications/Kicad/kicad.app/Contents/SharedSupport/scripting/plugins/HierPlace.py
sudo chmod 755 /Applications/Kicad/kicad.app/Contents/SharedSupport/scripting/plugins/HierPlace.py
Then hit Tools => External Plugins... => Refresh Plugins, or restart KiCAD.