For proving to everyone that yes, you can in fact do a clutter based panel without shoving it inside the window manager
I can see that they still plan to use Mutter in the next UNR, but I don’t really care – as long as users are allowed the opportunity to use another window manager, I’m always happy (whether that be compiz, enlightenment, kwin, xmonad etc).
Now if only one particular project could learn something from this.
edit: Damn, it looks like Unity also draws the desktop background. If they could just make it two separate X windows using rgba-glx (or the clutter equivalent thereof) then I could show off some really really cool tricks reproducing the famous “overlay mode” using expo and cube.