I was wondering about this earlier today. Not knowing as much about history as some of the fine folks here, I couldn't come up with much.
So what if Hitler had enough sense not to pick a fight with Stalin in 1941, and didn't waste all of that time planning Barbarossa? Does he overrun England instead? Does the U.S. join the fight sooner to help England?
I leave it in your hands, as I always enjoy reading what you guys come up with.