each hd69900 is 375W thats 750 for 2
how can you add TWO 6950 or 6970 (aprox 140W each) to a Corsair HX950W power supply

more sales hype

It's 2 GPUs per rig. Adding 2 more GPUs would be adding one more rig, which would include a new PSU.

That's not how I read it

Sorry, no, you're right. I'd missed the part about the non-6990s. However, both you and I missed the part about the larger PSU for the 6950/6970s.