Germany didn't carry out the Kursk offensive due to Soviet intelligence penetrating German high command and setting them up for a massive ambush at Kursk. Hitler wanted to destroy a sizeable Russian force located at Kursk which was bulging into the German lines so he began planning for operation citadel, a massive armoured attack designed to destroy that force.
Unfortunately he kept postponing the attack until the newer tanks like the Tiger, Panther and Elefant could enter production. Because of his delays, the Russian High Command soon learned of the German plans for the region and had ample time to set up an extensive network of defences which was designed to bleed and absorb the German offensive.
Haven't heard of Spielberg doing a bismark movie. Now that I've heard about it though I certainly am looking forward to seeing it when it comes out.
Still doesn't compare to seeing a thousand German and Russian tanks duking it out at close quarters at Prokhorovka though.