There's a lot going on with AMD these days. An apparently genuine slide with some specifications for Antilles, or the AMD Radeon HD 6990, an upcoming dual-GPU card has just surfaced here.
This tells us that Cayman, the GPU on which Antilles is based, has at least (and probably exactly) 1920 SPUs. It also tells us that the GPUs in Antilles are clocked at 775MHz, since it can output 3100 million triangles per second, and Cayman is rumored to be able to produce 2 triangles per clock. It's the only way the 3100 Mtri/s figure makes sense anyway, so this rumor must be true.
Managing to put a pair of such large GPUs at 775MHz in a 300W card is quite impressive, and from that, we an infer that the single-GPU Radeon HD 6970 should be clocked at 900MHz or above. I would estimate its maximum power draw at about 225W, perhaps a tad more since it features a 6-pin and an 8-pin power connector, providing the card with up to 300W.