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With respect to what has truly been a innovation by Nikon (over the past 5 years), only one lens comes to mind: Nikon 14-24mm f/2.8G ED AF-S.
As for why people would get a native 300mm F2.8 over the 200mm F2... size and weight for one thing.
Unfortunately for us DX users, wide primes are still nonexistent. Nikon camera bodies are great, but there is a severe dearth of attention toward DX primes.
... and it looks like Nikon has improved the build quality a bit too, which is a good thing...
I have not heard of a lens made of the non-metallic materials failing due to the materials.