Isn't Gnome-Do just a Quicksilver clone? Rythmnbox just a take on iTunes for Linux? Both are great applications, and arguably an improvement on the projects that inspired them, but I wouldn't say they great examples of innovation.
I should say though, I think people put far, far too much weight on "innovation" and "originality" (not mentioned here but along the same lines).
That said, it was more important for me that it was a tiling window manager, not that it was XMonad (it's simply the one I use). Dwm would probably work just as well.