It looks like we might beat Archimonde. It took a combination of two deaths to wipe us. I couldn't dig up the death reports. Sidecar's death is obvious in the video; a curse hits him, doesn't get cleansed, and he falls over dead. Ansawa's was a little more ambiguous, looked like maybe a doomfire or something. Both of the soul charges granted by those deaths smash our raid for uber badness, and we wipe shortly thereafter .... at 10% :)
Same sorts of silly mistakes we were making all night in previous attempts, they just cropped up a lot later in the fight, almost late enough that we won.