The whole piece is, as usual, smart. But this is a sideline quotable moment from Gruber's piece on Chrome this morning:
So I think Gnome and KDE are stuck with a problem similar to the uncanny valley. By establishing a conceptual framework that mimicks Windows, they can never really be that much different than Windows, and if they’re not that much different, they can never be that much better. If you want to make something a lot better, you’ve got to make something a lot different.