I've been playing with this concept for some time, to combine the simplicity of Gnome-Shell with the fantastic Launcher from Unity. This was for a while possible and relatively easy. The Natty edition of Unity 2D didn't have the dash button located on the launcher rather it was located on the panel. Unfortunately for this kind of layout isn't possible in the lattest version of Ubuntu, without major changes to the desktop. However thanks to some searching around the web I found the steps to make this possible without any of the flaws. Here is a short video over viewing the desktop.
Below I will attempt to outline the steps to get this same kind of desktop set up on your computer.
The link above allows you to easily download and apply the necessarily changes to the Unity-2D-Launcher for use like the above video. Enjoy.