Wii U sales trend may be just as expected if we look at Nintendo's home console sales.

[novasonic]

Without that silly trend breaking PS2, the same could be said for Sony. Clearly having a 2 year head start over the Cube and Xbox gave it an unfair advantage, and it's success can not be counted. I can now confirm lifetime sales of the PS4 will be 60m and the PS5 will be 38m