Probably the biggest reason that people are sick of WW2 games is that they all use the same fucking settings. Omaha Beach, Stalingrad, Market Garden, Pacific, and then always the same nations, USA, Russia, UK.
Despite this, there are a ton of battles and campaigns that are almost never touched, despite their importance. How great would it be to see a Canadian campaign? We got a mini one in COD3, but apart from that and a couple of missions in Company of Heroes, the Canadians almost never appear.
Then there is the Second Sino-Japanese War, which could be an entire game by itself. Of course, considering the brutality and the long standing animosity brought about by it, it might be for the best if it isn't adapted.
Now, obviously these new ideas won't happen, since most World War 2 games are directed at Americans, and what American wants to play a game about Canadians? (note, I know this isn't true of everyone, but from a marketing standpoint it is)
So, what sort of World War 2 game that doesn't focus on the conventional aspects would you like to see?