He still has so much to learn. Especially on offense. But the guy is such a hard worker and still so young, I think he could average around 25+ppg in the future. Next year I'm expecting around 20ppg from him. Then I think that will steadily rise until he reaches his prime.
On defense, he'll be fine. Multiple all defensive teams are in his future.
I'll say this... I'm glad we have Dwight on our team because I would hate to go up against a guy like Dwight Howard in his prime. That is just a scary thought.