The best value in this card will be to cross fire it with a 6950. One of the things not reported on by basically any website, is that the micro stuttering effect on all dual card crossfire / sli setups is much less pronounced on AMD cards where the primary card has a larger frame buffer and higher performance than the slave card.
There is benefit to purchasing two of the same card for crossfire, but there is a much better price/performance ratio with much smoother playback if you purchase a one bin lower secondary card for ATI setups. The only criteria for hybrid crossfire, is both cards have to be of the same prefix bin, 6970+6930 is no problem, while 6930+6870 is not possible.
I see this card being under high demand.