OMG - 840?

From wikipedia

Passenger capacity varies with the seat configuration chosen by the operating airline. While the A380-800 is certified for up to 853 passengers (538 on the main deck and 315 on the upper), achievable with a one-class configuration, Airbus references a "comfortable three-class" 525-passenger configuration in their marketing material [1] . Airlines' announced capacities range from 407 passengers (Korean Air) to over 644 (Emirates Airline, in two classes), with an 840-passenger one-class layout reportedly planned by Air Austral. [2] [3]