Well August is almost here and holiday start picking up in a month or two. Xbox One will be releasing in 3 times as many countries so people in those countries will be able to buy games and use online. The holiday is going to be absolutely packed will multimillion selling games.
By years end:
Xbox One will hit 11-13 million
PS3 will hit 16-17 million
Wii U will hit 9 million
80% of US sales are from black friday-christmas