The metaphor of cars vs trucks was used. For heavy duty work, trucks (Macs) will always be around. For everyone else, a car (iPad) will do just fine.

When the iPad nano was released they killed off the best selling iPad, the mini. Their statement on this was that they want to be the one to cannibalize their own products. If they don’t do it someone else will. Look at the iPhone, it made the iPod obsolete. Had they missed the boat on smartphones like Microsoft, they’d be screwed, as the iPod was half the business. Instead, they make way more on iPhones than they ever did on iPods. iPhone replaced the iPod sales and then some.