Apple is so big, it’s running up against the law of large numbers (Bernouilli theorem)which states that a variable will revert to a mean over a large sample of results" Growth will damp down soon. Someone will be tempted to do something dumb with the AAPL cash reserves. (Remember BRIC shares in BC that started fully funded by assets and were frittered to nothing by foolish reinvestments?)
Apple has grown by brilliantly cannibalizing the earnings of other industries. From commenter Popo at ZeroHedge: "AAPL has single handedly destroyed the entire media retail industry from Virgin Megastores down. It is laying waste to the digital camera industry from Olympus down, it has all but annihilated the handheld phone industry leader Nokia and it is devastating the industry leader Microsoft in the OS sector."
I like Apple products and own several but I see a lot of new competition out there. The iphone ("Man's greatest creation") is being overtaken by enthusiasm for smartphones like the Nexus, Galaxy Note and HTC One X just released. And Apple is about to tackle the giants of the television industry when that industry has already passed its peak.