Now the Smartphone only have 15% total cellphone market share, there are big growth potential for smart phone. The possible reason for AAPL going down is not due to its own business model (which is good), now there are more than 100 similar products introduced by other vendors,they are trying to grab market too. If AAPL cannot keep the current growth rate, the price of AAPL will go down, so AAPL has to develop new product to lure the rest of users to buy aAAPL products.
If AAPL can continue introducing ipad2 iphone5, etc., its stock price will go up more...