We have heard talk of secret sauce for the X1. Other than indie devs making a game for Sony, have we heard reports of the 50% more powerful PS4. (due to indie trying to kiss Sony's a$$) No third party devs have supported this claim.
Along with the power difference, we have also heard that/ the PS4 is easier to develop for. *Cough, Cough* Driveclub.
This article (wall of text) from one of my favorite sites. http://misterxmedia.livejournal.com/ explains Tiled Resources and how they make the X1 a unstoppable beast. There are some videos there that demonstrate this.
Also to support this. http://www.giantbomb.com/xbox-one/3045-145/forums/x1-esram-dx-11-2-from-32mb-to-6gb-worth-of-texture-1448545/
It also explains how Sonys console will be tapped out and the X1 will truly be a powerhouse for the next 10 years. It also raises the 4K gaming potential that's supports what MS said.
Flame if you want about the source but when this hits...................KABOOM!