Lason that is awesome!
I was worried if I put this cooler on I wouldn't be able to Tri-fire with a 6970 but if you could do that with another Accelero 6990 I'd have no problems.
Are you able to fit in a PCIE sound card too with that configuration? I was going to grab either an Asus P67 Revolution or Maximus IV to fit 6990+6970+X-FI and maybe an 8800GTX for physx.
No on this motherboard, with both these cards and coolers all the slots are now covered up.