Anyone who thinks this will happen needs to have their brain checked. Its quite reasonable to assume that in 2015, 1 console in 10 sold will be a Wii U judging by 2014s yearly sales (1 in 10 would actually require a drop in Wii U yearly sales actually, percentage wise). That would mean the PS4 has to sell 7 consoles for every 2 Xboxes sold, a ratio of 3.5/1! Considering in 2014 it didnt even make 2/1 that is a massive ask.
PREDICTIONS FOR END OF 2015: (Made Jan 1st 2015)
PS4 - 34M - XB1 - 21m - WII U -12M