Nikon officially announced the development of a new, next-generation full-frame mirrorless camera that will be "the result of Nikon's advanced optical and manufacturing capabilities gained through over a century of heritage" and "will work with the NIKKOR F mount lenses". Nikon specifically confirmed that it will continue to develop DSLR cameras and lenses in addition to the new mirrorless camera.
Additional coverage of the new Nikon full-frame mirrorless camera:
Nikon mirrorless camera announcement confirmed for August 23rd
More leaked pictures of the new Nikon mirrorless full frame camera
First leaked picture of the new Nikon mirrorless full frame camera (with Z-mount?)