The card has been tested under full load pulling 192 watt by a hardware review site who had their hands on the first cards
That full load was doing a heavy game for a certain amount of time, they also mentioned that if you overclock the card it will use more then 200 watt.
And including burnin with furmark now do not tell me you do not know how powerfull furmark is
Its actually more stressing cards then they will ever do in real time usage including mining