Nikon D610 is here. The update to the Nikon D600 is nearly identical, with a few updates. The first is a new slient continuous mode that can shoot 3 fps. The new silent continuous mode Qc can be seen on the rear photo on the mode dial.
It shares the same battery and gets 900 shots per charge. The shutter speed offers a maximum 1/4000 second and is built to withstand 150,000 shutter cycles.