Great post from Horace Dediu of Asymco :
Here’s the problem: If a company produces a string of successes, the conventional wisdom is that the chances of another success are precisely zero. A company is valued based on its cash flows and foreseeable improvements to them. What it’s not valued on is its innovation flows (and foreseeable improvements to them).
And conversely it seems that the market expects that a company with no recent success in innovation has a better chance of succeeding. See the jump in the Microsoft’s stock price after Steve Ballmer’s announcement. The expectation seems to be that the new CEO will be able to turn around and bring innovation. But Horace has a response to that as well : The next CEO is more likely to be remembered for being the one to kill Microsoft.