How about ET: Revolution
The problem is the market was previously saturated with WW2 and now modern warfare with allies vs middle eastern terrorism or Russians etc.
So instead why not a Police State (totalitarian Axis) vs The People (Allied) set now unlike in the future in some other games.
That way you could incorporate both WW2 weapons and modern weapons into the game. The People would have raided museums, or used home made devices, or got hold of guns from mercenaries etc collecting pre 90s guns such as Thompson, mg42 ppsh41 or AK47, and use improvised explosives etc. Whereas the State would have modern guns and with sophisticated gadgets and bombs, with hi tech Radio controlled car or quadrocopter as opposed to the people who would use a bodged rc toy car or rc toy helicopter.
Same classes as ET maybe different names depending on faction, spy instead of cov op, or scout instead of field ops for the people etc.
Need to obviously improve some of the underused classes in original ET such as the Covert ops and maybe the assault soldier.
Covert Ops/Spy - New weapons:
Decoy - via music player that plays a sound requesting a medic which has a “i need a medic” symbol appear on the map.
Pick Pockets - steal the ammo and small weapons such as hand gun or knife and grenades from the enemy.
Linguistics. If close enough to enemy can talk in or listen to their team chat, would obviously be more successful with a stolen uniform.
Spear gun(axis) or a medieval cross bow(allied) - for shooting underwater or silently.
Soldier/Assault - New Weapon.
Grappling hook with rope to climb things.
For air raids i guess the scout would need to “hack” into the police state and override their drones seeing as the people wont have an air force.
What with situations with the Arab Spring and the current crisis in Greece and the Euro it could be one step ahead of the game or at least be popular under the current climate.