It says "an increase of 20 bhp over the previous model. New standard 19” 10 spoke alloy wheels, new door mirrors and a revised anodized aluminum five-bar grille enhance the exterior styling in both the coupe and convertible variants. The interior of the new DB9 features a new centre console and a stylish key and docking station. Whether in Coupe or Volante form, it offers a supreme combination of driver involvement, character, luxury and refinement."
There are extensive changes coming in 2013-14. I think that you will see sleeker designs and lighter more efficient models. The boost in power will be minimal (10-15%). But I think that the engineering will bring the performance up.