This info came straight from Head today actually:
2013 will bring a new HEAD technology. We will use a new material called Graphene which enabled us to create a completely new and patented way to redistribute weight from the middle of the racquet to the tip and the grip. This provides more power and maneuverability in a lighter racquet! Novak and Maria will be launching this new technology in the Speed and the Instinct. We will also launch a completely new Power Series with 3 racquets that fit perfectly into HEAD segmentation: the Prestige PWR, the Speed PWR and the Instinct PWR! Why should only competitive players be able to use the best known racquets?
Solinco Tour Bite string