It's been 4 months since Call of Duty: Black Ops III was released and so it's right about the time Activision begin showing what's coming next for the series. Infinity Ward have announced on twitter that CoD 2016 is officially in development and many people seem to be hoping for a Modern Warfare 4.
Infinity Ward are the devs that brought us the ever revered Modern Warfare branch of the Call of Duty series, as well as Call of Duty: Ghosts. Many fans of the series have expressed a desire to return to the style of gameplay seen in Call of Duty 4 and Modern Warfare 2 so it'll be interesting to see in which direction IW intend to take the series next.
Last year, Call of Duty: Black Ops 3 made $550 million in its first 3 days of release and seems to be the biggest launch since Black Ops 2. Activision have been blaming the transition to next-gen consoles as the reason for the dip in sales since then. If that is the case, with the return of Infinity Ward to developing the series it wouldn't take a gambling man to expect the Call of Duty 2016 to exceed that figure considering the success of Modern Warfare 2 and 3.
The Call of Duty 2016 release date hasn't been revealed yet but it won't be long before the Activision marketing machine kicks in so expect to hear more details soon.