Not that anybody would make it, but I think a totally awesome mod would be an alternate reality WW2, where the Germans win at the Battle of Britain and the Battle of Stalingrad, and WW2 continues into the 1950s, and you get to see the late war inventions come to fruition.
Basically a mod where the giant folleys made by the Germans never happened, so the war continues to escalate and everybody starts using the really late war and prototype stuff.
The Germans and Spanish Army invade the British Mainland, and Push further into the Soviet Union and deliver more crushing blows; stalling the Soviet counter-offensive. The idea embodies all the "what if" WW2 arguments surrounding WW2, every turning point in favor of the Allies is a turning point won by the Germans. The Heavy fighting continues in 1949 with all the armies returning with their newest and best equiptment, such as the Panzer Maus, the T-28, the TOG-2, the E-100, and Assault Rifles such as the STG44 in mass quantities, Eugene Stoner's AR-10, The Belgian-designed L1A1, and of course the SKS and AK47
Battles take place in Eastern Russia & Siberia, Western France and the West Coast of Britain & Ireland