I call bulls*it on this the whole X720 being 2-3 times stronger than PS4 thing. Consider what Tretton said:
Being the best and being 2-3 times weaker than your main competitor doesn't really make and sense. I expect PS4 and X720 to have 10-15% difference in power.
And X720 being 2-3 times more powerful would also mean that Microsoft would have to price it substantially higher than PS4, unless they are willing to suffer a meaningful loss per console sold.
Tretton is an idiot, but logic says that this will never happen. I am not sure people realise how big difference is 2-3 times. So basically we would have low end (wiiU around same power as current gen PS360), then middle ground PS4 6-10 x? over WiiU/PS360, and then 2-3x what ever PS4 is for 720! Yeah I am sure publishers are all over this idea, if they want to commit suicide.
PS4 and 720 will be almost identical. 3rd party will stear them in that direction.
Besides Sony is under the biggest pressure of all of them. PS3 runs games like TLOU and Beyond. Now how much better PS4 has to be to convince people it's worth their money? I say that's a lot of pressure. So again 2-3 x is fanboy dream.