Tim Cook's apparent inability to manage Apple's product roadmap worries me. It seems every new product or update is dogged with delays for whatever reason. He needs to forget the stock market and focus on a more achievable product cycle.
Having worked for UK, US and Japanese IT firms over the years I think this is a particularly US centric problem. When I worked for the Japanese IT firm I was asked to provide products plans over 3, 5 and 10 years because they valued long term development. When I worked for the US IT firms I was rarely if ever asked to look past the next quarter or at most the next 12-18 months because their entire focus was on quarterly earnings. Nothing else mattered.
I see the same apparent issues in Apple today. Forget about the share price. Solve the production problems before you release the next iMac, etc.