I stumbled onto this thread on Reddit, but while the question is really interesting none of the answers is of much help.
Has anybody tried installing it in Freya?
It seems like it does not work anymore.
This is possible in Luna but you can't do it in Freya because it depends on super-wingpanel: http://ubuntuhandbook.org/index.php/2014/01/global-menu-elementaryos-luna/ The dev for super-wingpanel abandoned it so it won't run in Freya. SeriouslyLaughing - On the reddit thread you've posted.
But the only way to be sure is to try it yourself. You could create a virtual machine with elementary OS to test it with, that way you don't harm your system.