Well I personally think that there are craploads of areas to be explored of WWII. However, developers will never get to them becuase americans wont buy a game in which they play as a soviet or german soldier, because of their stupid prejudices.
I mean, Stalingrad, Kursk, Finland, Italy, the japanese invasion of China...
There are craploads of unexplored scenarios that could really be cool if approached inteligently.
For example, I just shudder to think of a game that would accurately represent the battle of Kursk or Moscow.
Instead, you just get to play as American soldiers, that didn't even participate in any of the major battles of WWII.