They claim it's essentially two 680s in sli on one card. This maybe a more compelling proposition for resolve performance than the 680.
Currently Kepler cards do not function on the Mac, and the gtx680 on the pc seems to be on par with the gtx580 in terms of resolve performance. They have switched some functions which were formerly chip based to software based, so performance could be improved in future driver updates. But cuda performance was not the main focus. Currently the 680 is not a compelling choice for resolve. But two of them on 1 card may very well become.