(news and commentary)
Nikon has posted firmware updates for the D4 (A1.05, B1.03), the D600 (C1.01), D800 models (A1.01, B1.02). Note that the D800 and D800E require different update files, so pay attention to the link you're using if you own one of those cameras.
All cameras get EXIF support for the new 800mm f/5.6 lens. The D600 and D800 also get an improvement in subject tracking performance for continuous focus mode (previously made on the D4). In casual testing, it appears that there is an apparent increase in focus performance for moving subjects while tracking them, just as there was with the D4's earlier update.
The D600 also gets a fix that provides 100% output size for video on the HDMI port and several bug fixes. The D800 meanwhile, gets better display of gamut on the color LCD when using AdobeRGB as the Color Space, while the D4 and D800 get a change to Live View exposure when in Manual exposure mode, plus several bug fixes. The strangest modification is this one for the D4: "Images are sharper and appear more three dimensional." I have no idea what that's referring to, though I suspect it must be a JPEG/TIFF change.
Unfortunately, one wished for change: a return of trap focus capability, is still missing in action.
(An earlier post noted that the new Live View function replaced the old. It does, but you can get the earlier method by pressing the OK button while in Live View.)