There are strong rumors that the 2013 new engine formula will have completely unrestricted KERS. Surely a big part of the change will come from AW KERS. This is going to have an impact on chassis design if you only think about the need to supply torque to the front wheels and collect it from there.
If we just assume that KERS will be electrical you still have intriguing consequences. The front wheels will need drive shafts. The brake/motor/generator function will probably go at least partially inboard. That should increase the mass in front of the driver's feet considerably and will cause new safety measures to the tub and the suspension/drive compartment at the front of the tub. Energy storage for the front wheels will be required either in the front compartment or connected by use of energy carrying cable ducts through the driver compartment to the rear energy storage.
There is also the question of how dual torque drives to all wheels will be regulated to avoid traction control and ABS.