Nikon tends to stockpile a camera body before announcing it. This is part of the reason for so many leaks, since printers are printing manuals and other documents to stuff in the boxes, and someone always leaks information.
Actually, I think it works to Nikon's benefit, since they get free advance advertising, and interest builds up. If only they had good lenses for FF at reasonable prices. They had optimized many of their older FF lenses for crop as well as continuing to spend resources turning out new crop lenses such that they find themselves with fine FF cameras, but a limited selection of high quality FF lenses.
Its becoming pretty obvious that FF cameras are rapidly moving to mainstream for photo enthusiasts and they find themselves in a hole.