Last year, PowerColor unveiled its Devil 13 HD 7990 video card, which packed two Tahiti XT cores on a single PCB. At the time it was more of an unofficial HD 7990, since only PowerColor has branded with the 7990 label. However, all of that is soon to change as AMD has officially teased, for lack of a better word, its dual GPU monster known as, what else, the HD 7990. Details are beyond scarce on this card aside from a picture and the fact it'll have two 7900 GPUs, three cooling fans, and is "whisper quiet." It also features four mini DisplayPorts, one full size DVI port, is believed to be powered by two 8-pin PCIe connectors, and is a dual-slot card. AMD showed the card off during the Game Developers Conference, going on now, and called it the "world's fastest graphics cards."
Hopefully more information and exact specifications are revealed soon, but it's expected to launch sometime in the next several months. The HD 8000 series is on track to arrive by the end of this year, so it's reasonable to believe AMD wants the HD 7990 out well before then.