Ps4 will keep growing in the next years, price cut to 249e or 299e, premium model at 449e or 399e, Gran Turismo, Cod, BF, GTA, RdR etc etc... Huge brand etc etc...
Xbox One will keep selling worse unless they introduce a Slim Version at 249e for the rest of the generation and make it 199e even, introduce Xbox One Premium at 449e with super power like Neo or better to gain some milion hardcore fans and they might catch 360 or outsell it.
Wii U is dead and should retire soon, same for 3DS, NX should replace them and i dont know what to say about it, i think it will be a huge flop since Nintendo is so distant from gamers and 3rd parties so we shall wait and see.
360 has already been discontinued and Ps3 will be aswell.