The next gen really starts when all systems are out, at the moment i'd say we are in a transition period between gen 7 and gen 8, since only some of the next gen systems are out at the moment
Xbox One, PS4 and Switch (+ Many Retro Consoles)
'When the people are being beaten with a stick, they are not much happier if it is called the people's stick'- Mikhail Bakunin
Prediction: Switch will sell better than Wii U Lifetime Sales by Jan 1st 2018