The only issue would be, the 6990 will take the fastest AMD card available crown quite easily, it should be a decent wedge faster than the 5970 and in some situations, tesselation/uber high res(as most sanely priced 5970's were 1gb per core, not 2gb) massively faster. In silly 2560x1600 res and high tesselation games the 6990 could be 3-4 times faster than the 5970.
If the 59x gtx or whatever its called is 2x560gtx's, it will struggle to beat a 5970, a card over a year old, it won't be 70-80% faster than a 580gtx, and it will be rather pointless. Good value they might be but thats about it. But who knows what it is, one website suggested its possible theres more than 4 chips on the other side of the pcb(the normal side) which is possible but insanely unlikely. Thing is someone who took the pics seems to have confirmed they ARE 128mb chips, not the new double density chips.
That means, of the EVGA card at least, that its like 95% certain to be a 1gb per core, 256bit bus card.
Its still possibly gf110's, even potentially with full cores but heavily cut down bus. Remember the bus, trace routing for memory is the MOST pcb intensive, expensive, power hungry, complexity increasing thing in producing pcb's. However, 2 full gf110's would be severely bandwidth and memory limited at 256bit bus and 1gb mem.
Though, downclock the cores enough and they'll not be fast enough to need the full bus.
Cost wise, heat wise, yield wise, profit wise, 2x 560gtx's makes infinately more sense than HEAVILY cut back gf110's. 2x580gtx with limited bus/memory reduction makes the most actual sense for the highest speed card they can hope to make.
It really will be interesting to see which way they go, no dual card seems almost less of a statement of failure than having to go for a dual lower end core card.
In reality theres few situations anyone HAS to have a single card vs two cards these days, 2x 8x pci-e slots is more than enough for ANY xfire/sli setup, which means just about any chipset/mobo can deal with xfire/sli these days.
The one single advantage to dual gpu's on one card is if it is the single fastest card available, but a large margin. If its not particularly fast, theres very little reason to not buy 2x 560gtx's in the first place.
