Coming back to Apple, this is precisely what Steve Jobs mastered. He had a knack for disrupting his own product lines.
In June 2010, Apple launched iPhone 4 and it has barely been a year and we are already getting confirmed reports that iPhone 5 is on its way. And all of this when the going has been so good Apple only recently toppled Nokia as the most successful handset manufacturer based on revenues. See chart below:
And what has the series of iPhones cannibalized? iPods, of course. At the end of 2008, Apple had sold 22+ Million iPods and in the first three quarters of 2011, they have only sold 8+ Million iPods. But is Steve Jobs complaining? Not at all so what if iPhone 2, iPhone 3, iPhone 3GS & iPhone 4 have cannibalized iPods and also each other? As far as Apple is concerned, they have always walked away with higher profit margins than before.
And what did iPads cannibalize? Low-end Mac Books. Again, Steve Jobs wasnt worried.
When iPhone 5 comes out, iPhone 4 will get cannibalized. Steve Jobs might not be around to see the cannibalization happen but I sure hope Apple continues the tradition and doesnt miss the plot in Steves absence.