Nikon announced development of the D850 but gave little official information. However, the leaked photos of the D850 and some specifications have appeared on the internet. It is said to have a higher resolution 45-46-megapixel sensor, improved low-ISO capability and high ISO performance. Moreover, there is also a new version of SnapBridge, tiltable LCD screen, dual memory card slots and the autofocus system from the D5.
It is rumoured to shoot faster than 8 FPS. The 850 could feature DX sports mode that shoots 9-10 fps but slows down to reasonable 3-5 fps at full resolution. It could shoot full-frame, full-resolution shots at this rate probably. Another exciting news is that it will handle 4K using the entire area of the sensor unlike the current crop of flagship models.
This makes the D850 a dream of a Nikon with all features people would want it to have. It will have distinguished and truly professional body it seems with improved button layouts, articulating LCD, back-lit buttons, and top-end weather sealing. All these big-time features will come at a premium but nothing is sure of the pricing yet.