It is now clear why the various insiders said what they did about the flops and bandwidth arguments being worthless and about efficiency. The 'special sauce' is the entire design philosophy targeting the removal of highly redundant processing inherent in modern graphics engines in the first place.
Make no mistake, the DME's and eSRAM are most certainly NOT there primarily to alleviate DDR3 bandwidth issues, as we all previously had assumed. DDR3 was NOT chosen just to be cheap, it was chosen more likely because higher bandwidth was simply not needed and to help with the thermodynamics. Think about it like this...
Sony went with a largely off the shelf, simple design for decent power at reasonable costs. MS could have very easily gone with the exact same setup. But they didn't. They evidently looked at the obvious setup and opted to spend more money at higher costs engineering a very elaborate, highly customized architecture that will be challenging to manufacture. Why? None of that helps the OS or even Kinect stuff one bit as far as anyone has been able to tell. So even in purely gaming terms they opted out of the cheap, easy, straight forward approach. They wouldn't spend all that extra money and effort and risk if both their engineers and AMD's didn't feel it was worthwhile.
It's not about one magical piece of hardware to make up the bandwidth of Flops difference as a 'secret sauce'. Their ace in the hole is designing the whole architecture to be 100% catered towards virtualized texturing, robust tiling, virtual geometry, low cost post processing fx, etc.
And btw, we DID hear a rumor from VGLeaks saying the specs had been adjusted. Nobody noticed that evidently. 
