They'd need to if they are sticking to their provisional release dates of 2014/15.
If Moore's Law is anything to go by...
NES 8bit
Megadrive 16bit
Playstation 32bit
N64 64bit
Dreamcast 128bit...
Future GEN needs to be twice as good as the Wii2 otherwise the same thing will happen as it did 6/7 years ago, the Xbox came out WAY before the PS3 and people needing a next gen fix when out and got bought one, losing their allegiance to the Sony brand, when the PS3 came out, sales were terrible... Still are really, due to price.