"Christensen doesn’t criticize managers, as many ivory tower professors do in their books. Rather, a major theme is that great managers miss disruptive innovations precisely because they’re focused on their customers, working hard to create returns for shareholders, and trying to do everything right."
There’s an excellent interview with Clayton Christensen, the author of The Innovator’s Dilemma, today in Business Week. His seminal work on the nature of disruptive innovation is now ten years old. One particularly interesting thing he addresses in the interview is the way that the notion of "disruptive" has been somewhat hijacked by corporate managers to describe any new, bold initiative, with the implicit understanding that the initiative is going to return huge growth (which Christensen says is not often the case with truly disruptive technologies).
He also predicts that the iPhone won’t be a game-changer for Apple since it’s what he calls a "sustaining" technology (as opposed to a disruptive one).