Nikon has published firmware updates for the D700, D300 & D300s DSLR cameras. The updates add support for the AF-S NIKKOR 800mm f/5.6E FL ED VR lens.
From Nikon:
Modifications enabled with this upgrade of firmware, release date May 21, 2013
Installation Instructions
Nikon D700 - Windows | Macintosh
Nikon D300* - Windows | Macintosh
Nikon D300s - Windows | Macintosh
* NOTE: Installation instructions for the D300 are identical to the instructions for the D300s.
Firmware Downloads
Nikon D700 Firmware A:1.04 / B:1.03 - Windows | Macintosh
Nikon D300 Firmware: A/B 1.11* - Windows | Macintosh
Nikon D300s Firmware: A/B 1.02** - Windows | Macintosh
* NOTE: This update is for the D300 model only, and not the D300s. Do not attempt to upgrade the D300 with this firmware.
** NOTE: This update is for the D300S model only, and not the D300. Do not attempt to upgrade the D300 with this firmware.
B&H carries the Nikon D300s DSLR camera.