Earlier quoted context omitted.
I feel as if this article has a strong tinge of exaggeration (See: ".. ALL desktop ...") and you make some good points too. I haven't tried Gnome3 extensively and daily I use Snow Leopard (On my MbP while I'm out) and Win7 (Main desktop machine) and Gnome3 and more specifically, Ubuntu 11.04 with Unity, hasn't really caught my attention in any huge way. The new sidebar on Unity reminds me of the Dock and the new Win7…
'Spaces' aren't new They aren't new but they've been fairly common in Linux desktop environments since the 90's while OS X didn't introduce them until 2007. I'm not sure where they first appeared but at the very least they've certainly become a common idea because of Linux.
Also, while Project Looking Glass (Sun) may have borrowed some stuff from Quartz, Apple borrowed a lot of UI stuff from Project Looking Glass