Actually it would have made more sense to produce the cards in 2 versions, SLI and Crossfire.
I am not at all impressed ny the idea of integrating the 2 together, it's just a burden on the consumer, No one is going to use sli and crossfire at the same time.
I remember some time back some mobo maker had put sockets for both AMD and Intel on the same borad, which was a poor idea, i think it's the same thing again.