Do successful companies still need to innovate?

In a recent post at the Harvard Business Blog, Scott Anthony asks the question if successful companies should still focus on innovation? Most of the time, they're so far ahead of the game with their current products, why bother wasting billions of dollars on a product innovation that has the possibility of failure? Anthony believes companies should. Why? With companies that are already widely successful, they have the capital to spend on new product innovation. They also have developers and assets to foster the innovative spark, and a company always has room for growth. Anthony points out that a new era is coming when innovation from within the company is vital. He pointed out these companies that are proving this point: Procter & Gamble, Johnson & Johnson, General Electric, Cisco Systems and Amazon.com. What's your standpoint on successful companies innovating? Are those who are failing to keep up with the new trend of improving and inventing their products going to loose their status as successful companies if they do not work at coming up with new products?