Playstation 4 will be all about motion controls, slightly better gfx.
Wii u will be ps3 with wii controls and a drawing pad.
Xbox 720 will be incorporated into windows somehow and combine gaming platform with PC
my speculation, xbox theory is exaggerated.
2015 I wouldn't mind PC becoming main gaming platform, think of all the developers going to PC with commerical titles modable and the GFX pc gaming would be booming and it would get expensive fast