Breja: If Witcher 4 happens at all, it will not be 2017. The first one was in 2007, the second in 2011, and the third will be in 2015. That's 4 years between games, no way another happens in just two.It's CD Projekt Red and the Witcher, not Ubisoft and Assassin's Creed.
Of course, SOMETHING might happen in that time, and I doubt Wild Hunt will be the last we see of Geralt. I for one would probably enjoy Tales of The Witcher from TellTales, if CD Project could make a deal with therm like Gearbox did about Borderlands.
and recently released The Witcher Adventure Game, I think it safe to assume we will see more spinoff games.