Before the WWII broke up, the idea of the infantry support aircrfat was developed into a CKB-55 prototype wth the production started in March 1941, just before the attack on Soviet Union. Unlike the prototype, the serial Il-2 aircraft were single seat and a wings and rear fuselage structure were made of wood.
Nevertheless, the losses led to further development of IL-2M version, which brought back the rear gunner, and become standard from the end of 1942 till January 1943 when another major modification, IL-2M3, was put into production.
The losses were very high, especially of the gunners and 1/3 of all flyers decorated by the "Hero of the Soviet Union" belonged to the crew of Sturmoviks. But the idea proved itself and alltogether, there were some 36 163 Sturmoviks build.
The succesor of Il-2 was Il-10, which came just ofter the war and was used by the Air Force of Eastern block countries and e.g. in Korean war.
More about Ilyushin Il-2M on wikipedia
June 2009