Nikon has released it's Nikon AF-S NIKKOR 300mm f/4E PF ED VR Lens
. It's available for preorder via B&H and will ship beginning Feb 5th.
Weighing only 1.6 lbs it's the lightest 300mm f-mount lens available. "Speed, light weight, reduced size, and features that fulfill a long technological wish list make [this] a lens Nikon shooters will crave for their kit." Check out the pricing and full specs list here