The answer is obvious, two 7950s are a FAR better deal than a single 680 at the SAME price.
I gotta love Nvidia's price gouging, making people buy AMD gpus. Which is nice, because AMD needs more customers. I initally wanted to buy a 670, but then i saw that the 670 is as much as a 7970 in my local area. So the decision was a no brainer.