I dont think a comparison of the 3870X2 being a single card can be compared to the C2D's and C2Q's. The C2D's are multi threaded processors, so providing the 2nd, or 2nd 3rd 4th cores respectively, into one package. Where as the 3870X2 is using 2 entire singular cores, on there own sockets and implements the same crossfire technology as i am using with my 2900pro's. I agree, they have cramed it onto one PCB, and now there is a short version, it isnt too much bigger than any high end card. However the point still remains its using the same technology as a multi card set up. IT IS STILL CROSSFIRE. If it was a multi-threaded processor and could run it all through the same socket, i could see this as a generative shift in results, but this isnt, they are using the same technology, just implemented in a different means. IMHO.
EDIT: No idea why i have Oldguy932's signature?