I'm thinking AWS needs to implement the Availability Zones: AZ-ChaosMonkey and AZ-ChaosApe. Having a dedicated playground for breaking things where they can start to observe how this complex system reacts to simple failures and gaps in assumptions.
I just got my 2011 15" - opened it up to put a new SSD in it and found that the heatsink/fan combo off to the back corner was missing all the screws that would have secured it. I bet this doesn't help. I have yet to run into any issues but haven't done anything to stressful with it.