I agree, it is too little, too late.
GNOME 3 has been compared with OSX, but it didn't copy the functional aspects that made OSX good- it only copied the cosmetic aspects, which made the desktop broken. It's got something that looks like a menu bar on the top, but it doesn't actually function as a menu bar- it just takes up space. It's got something that looks like a dock, but it can only be brought up through a full-screen launcher. It doesn't even have a persistent taskbar of any kind: You have to perform an extra action just to see a window list.
There are many ideas in OSX that could be used, ideas that are really good- but cosmetics isn't at the top of the list.
Global menu bar? Maybe. Some people like it, some don't. It's nice as an option. Unity really screwed up by making the global menu take up space but stay hidden until it's moused over. That's blatantly anti-usability.
Only one "System Settings" or "Control Panel", with all settings living in logically organized applets. This is something the Mac does really, really well. All "sharing" settings live in one "sharing" applet, for example. Linux still has problems with functionality being duplicated, or split up into different control panel applets because various under-the-hood things are taken care of by different software. The user doesn't care whether window effects and menu fonts are taken care of by different software- they just want settings to be easily found.
One, universal "system tray" with icons that convey information quickly. OSX does this well, Windows has played catchup but its systray icons aren't quite as readable- Just think of the volume icon, for example. GNOME has tried to do this, but they're all plugins and they aren't compatible with the systray applets that have been in use up to now, hence the hidden floating systray in the lower right for legacy applets. How was this let out the door? It's almost as broken as Windows 8.
The various software that makes up the desktop should have self-explanatory names. The file manager should be called "File Manager". The text editor should be called "Text Editor". People are rightfully confused when they see "Caja".
Of course, this is small potatoes compared to the awfulness they've foisted off with Windows 8. As Microsoft abandons the desktop and users look for a proper OS, I'm holding out honest hope for a Linux desktop with some real usability and polish. Just... for everything to feel like it was developed as a whole.