Robert already touched on this, but the sound designers, just place the sound where they want it in the room on a GUI and the Atmos processor does the rest. This is because there is no standard for how may speakers an Atmos theater will have. There are some with as few as 26 (could be lower now) and you could have some with up to 64. The Atmos processor in each theater decodes the mix and decides based on the number of channels in that specific theater where to direct the sounds in the mix. During a demo I saw a mixer take a sound and with the mouse move it all over the room in real time. As to blown speakers, they system does a self test each day looking for speaker problems. If it finds a problem it sends a repair alert and routes around that speaker until it can be fixed. There will be a big roll out in 2013 with over 1000 screens world wide. A lot of next summers blockbusters will be mixed for it as well.