Godrulz,
You miss the point entirely. In this case, for David to take the census was wrong. God was not ignorant of this. And yet, God moved David to take it. The point is that God ordains everything, and we are still responsible.
The Open Theists claim that if God ordained everything, than He is responsible for commiting evil. But the Scriptures tell us otherwise! God DOES ordain everything, and yet, WE are still held responsible for our actions. God made David take the census, and David was still held responsible. David didn't not say, "Well God, you can't punish me for taking the census because you moved me to do it". On the contrary, David confessed that HE sinned before the Lord! And he did. Yet God made him do it.
God did cause David to take the census, but He did not cause David to sin. David was responsible for his own sin. God meant this for a greater good; David meant it for other, selfish, sinful purposes. This can be applied to everything that happens in life! God ordains everything, and His intent is of a good cause. The intent and motive of the individual involved in the ordained action may not be so great, and thus they sin. Though God ordained the very event, the person involved is still responsible for thier sins.
This is the Calvinistic viewpoint, yet Open Theists have wrongly accused the Calvinist for believing that for a person to say God ordains everything is to claim that He is responsible for our sins. That's just not so! No Calvinist believes that. This text in 2 Sam. 24 thus refutes the strawmen built by Open Theists that accuses Calvinists of blasphemy.