While there is another thread
(here, by the way), this is specifically concerning the agreement of the test, along with confirmation from both the EU & USA of it's validity:
European and US air safety authorities have approved last weekend's evacuation test of the Airbus A380 super-jumbo, the aeroplane-maker has confirmed.
Approval from the European Aviation and Safety Agency and the US Federal Aviation Administration confirms the plane's maximum 853-person capacity.
With that in mind, I'll leave this thread open. 853 passengers, here we come! [:0]