Along with the newly released 300mm F2.8 Nikon also made a surprise by launching a 2.0x teleconverter, they have until now been reluctant to release.
Nikon writes : “AF-S Teleconverter doubles the effective focal length of select compatible NIKKOR lenses, offering an affordable and portable gateway to extend telephoto reach; ideal for sports shooting, wildlife, surveillance and more.”
Read all about it over at NIKON