not quite Steve, the ATESSA system is designed to deliver torque to the front wheels whenever a loss of traction is detected in the rear. There is no distinction between forward motion and lateral motion.
I have on many occasions driven R32 GTR's around the circuit and made full use of the 4WD system mid-corner and on corner exit.
And for the record, James is spot on with his tyre breakdown. high grip = softer compound = higher wear rate.
This is the way it goes and in the pursuit of the perfect balance between grip and longevity, sacrifices need to be made. Whichever tyre you decide to go with, your wet weather grip is largly dependant on throttle input/position. I have driven cars around the 200rwkw mark on BRIDGESTONE Potenza RE-01R's (Bridgestone Japan's absolute top of the range/high grip road tyre for those that don't know) in the wet and the use of full throttle only resulted in a loss of traction. This demonstrates that no road tyre is going to keep 100% traction in the wet if the driver is not careful. By being very gentle with the throttle (not just how far you apply it but HOW you apply it) you can control the car quite easily even in the rain.