Think of the fielding, folks! Noone ever thinks of the fielding. Here's the cricinfo commentary from the Perth match in December:
2.5 Ntini to Ponting, OUT, Ponting goes first ball! Would you believe it! Ntini bowls a fuller ball on a length, he pitches it just outside off stump, Ponting goes hard at the ball off the front foot, he is looking to push on the off side but gets a thick edge to AB de Villiers who takes a low catch at gully
5.2 Steyn to Hussey, OUT, Hussey's gone for a duck! He pushes forward at one that slants across him and gets a thick outside edge which flies low towards third slip, de Villiers dives forward and grabs it inches from the ground, terrific catch, what a fielder he is, Steyn's celebration is intense!
MEK Hussey c de Villiers b Steyn 0 (11m 7b 0x4 0x6) SR: 0.00
59.5 Kallis to Lee, OUT, what a catch!!! an absolute stunner. short of a good length outside off, Lee gets on the back foot to guide that past point, gets the outside edge and de Villiers dives full length to his left at second slip to pluck it out of thin air with both hands. Australia seven down now.
B Lee c de Villiers b Kallis 5 (8m 6b 1x4 0x6) SR: 83.33
79.4 Kallis to Krejza, OUT, stunning catch! By who else but AB de Villiers! Kallis angles a full ball into the right-hander, Krejza tries to drive off the front foot but the bat turns in his hand and he slices the ball off the face towards point, de Villiers leaps to his right at full stretch and takes the catch with both hands inches off the ground, what a sight! Terrific effort
JJ Krejza c de Villiers b Kallis 32 (81m 63b 5x4 0x6) SR: 50.79
That's in one match! The first was a difficult take, but the other three were all but impossible. And he went on to score an unbeaten century to chase down 414. The value of a player like this in the field is massively understated. I'd say South Africa could not have won that match with any other batsman in the side instead of AB, for that reason.