I would love a WWII themed Battlefield running on FB2. But they aren't going to make one, and I am actually kinda glad. Why? Because I can't imagine any kind of progression system, that would give you access to new weapons as you rank up... I mean, WWII was a heavily themed conflict and not just when it came to theaters but even the nations themselves. For every map you would have a different set of weapons - just like it is in FH2 (now I realize there could be many more kits if it was possible per map in FH2 but still, there's a limit). Say, there would be ETO and PTO - they would need to restrict what weapons you can actually use in different scenarios (maps) so that the game wouldn't look hilarious. Or they could focus on just one theater of operations... But then there are "weapon unlocks" - well, there weren't any in WWII. No flashlights, no lasers, no scopes... the only thing that would be kind of sensible to make an unlock of would be a sniper scope.
So basically a "proper" WWII Battlefield (the way I would be willing to pay for it) couldn't come with unlocks/progression system (actually maybe you could unlock some things like more nades and little things like that, but certainly not in such a scale as it is in BF3) so it wouldn't look retarded and would follow at least the basics of history. And I want the next WWII game to be "serious", not just another 'BF Heroes'.