At home, I use a Mac and a pc running Ubuntu Linux with Gnome 2. At work, I use a pc with Windows XP.
Gnome is an odd mix of Windows and Mac OS X influences. It's a very simple interface in many ways. You can find your home folder, Internet apps, wifi with a single click. On my Acer, which is a fairly basic laptop, it's fast, stable and reliable.
It's hard to tell where any of these three interfaces copied from
each other. I've seen a post online claiming that Gnome had virtual desktops before Apple did. Gnome seems to have copied the Dock concept from Apple but Solaris and OS/2 both had dock equivalents before Mac OS X appeared. And perhaps, to be fair, Next may have had a dock as well.
Most cars work the same. Most phones work similarly. Bicycles work the same. These are all interfaces.
So, is it innovative to copy from another interface? We're more productive because we can swap from one interface to another without losing pace, whether it's a car or a computer. Commentators often call interfaces innovative but we can really say something is innovative when it's an improvement on what went before and when it's A New Thing in its own right, not just new in the context in which we see it.
