Nikons main news at CES is the D3300 DSLR, but its making a more unusual announcement as well. The Japanese camera giant has revealed that its working on the Nikon D4S, an upgrade to its current flagship DSLR, the two-year-old D4. Nikon says the D4S will feature improved image quality thanks to a new image processor, and the autofocus system has also received a boost. Nikon isnt letting on when the D4S will be released, or how much it will cost.