I heard they weren't going to release a 4WD 911 Carrera for the 997 body. The 996 model was only released in 4WD form because it was a test of the 4WD system that was going to be used on the Cayenne. Now that there is nothing to test out, and since the 997 911 has such a better suspension setup, there is no need for a 4WD 911.
Definitely a great-looking car, though!