It looks like AMD will be launching a dual-GPU card sometime in the second quarter of 2013 and that two 8800 Series cards are scheduled to ship this quarter.
But it appears that AMD is having a few problems. If the roadmap is still being followed then the company is fast running out of time to make it so. It might be that the roadmap is out-of-date which is why no one really cares much that it has been leaked.
But the roadmap does contain some interesting specifications. The Radeon HD 8990 (Venus XTX) appears to be two 8970 GPUs combined on a single PCB.
The card will be huge and will have 5.1 billion transistors distributed between the two GPUs. It will also have 5,210 stream processors and 160 texture units per core.
The 8990 has 48 ROPs per core and a pair of 384-bit buses. Memory will be 6GB to 12GB and should be clocked from the factory at 1,250MHz. The roadmap said that each GPU will ship running at 950MHz with the wind behind it and if it is going downhill.
The card will carry a maximum TDP of 375 watts and that each core and memory set will be clocked slightly lower than a standalone 8970 GPU.
A single 8970 will run at 1050MHz core / 1500MHz memory which means that the card is not as powerful as the sum of its parts. You would get more grunt if you had two individual 8970s but the up side is that it will take up a lot less space.
The card can manage DirectX 11, Shader Model 5.0 and OpenGL 4.2 and we are guessing that it will cost more than $1,000 if it ever ships.