Agree with a lot of what has been said about SA's batting line-up. It's vital sides try and get into that mid-lower order without too much damage. The top 5 looks excellent, De Villiers is now one of the finest ODI batsmen around, Kallis continues in his own exceptional way, Amla is in tremendous touch, Smith rarely disappoints, and if Duminy can show in this WC the flashes of class he's shown in the past, he will be pivotal to SA getting the big totals. The problem is if, and it is an if, a side runs through the top order, do Du Plessis, Peterson, Botha, etc have enough to do a job, serious question marks at this stage imo.
As for the bowling attack, two very good and very different spinners in Botha and Tahir, should the pitch be conducive to spin, then there's Peterson, Du Plessis and Duminy to use. While Steyn, Morkel and Kallis is a decent trio for pitches with a bit more in it for the quicker bowlers. It looks to have most angles covered, but at this very early stage, my concern for them would be the depth of the batting.