Rumors indicate that Porsche wants to introduce the 997 Carrera 4S next summer as a MY 2006 car. Power is rumored to be 355 HP (same as Carrera S).
The C4S is rumored to be 17 mm wider in the rear compared to the 997 Carrera/S. Unfortunately I didn't pay attention, so it might be 17 mm on each side which makes sense. Pretty wide in my opinion! A C4 S Cab is planned for spring 2006. Again: RUMORS. As always, take them with a grain of salt.