BFGoodrich, in conjunction with Airbus Industrie, has began testing an evacuation slide/raft demonstrator for the double-deck A3XX. Airbus is proposing an 18-exit design for the basic 560-seat A3XX-100, eight of which will be on the upper deck. As the internal stairways can not be used for evacuation, up to 250 passengers will have to leave from the upper deck exits. Airbus says that it "-can achieve velocities at the bottom of the slide which will be within the range of slides on the A330/A340".
Source: Flight International