Every new technology introduced to racing allows teams to develop a secret advantage. Rules are adjusted over time to balance things out. But you can be sure that by then another new technology will have been introduced. The KERS system is already producing lots of results that are trickling down to consumers. I can imagine how using the torque and resistance of the electric motor as a means to increase grip is something that may be used in standard cars. Rather than using the braking system, this could be a smoother option.