I'm getting a bit stoked about this...
Between large scale battles, commando strikes, infiltration missions, counter-espionage and political intrigue there's definitely a lot of potential.
I'm simmering my own new 4e campaign; I've been using WW2 as a source of inspiration to plot out the grand scheme. I've got to agree there's a lot of potential ground there...
--obviously, engaged in a big battle (whole range of variations here, depending on who's winning and specific situation)
--escorting refugees through contested territory
--delivering vital supplies to a besieged city or fort
--liberating prisoners from an enemy camp, er, dungeon
--destroying a key enemy research/resource/ritual facility
--extracting (or inserting) spies from neutral or hostile territory
--escorting diplomats to/from neutral or conquered states
--protecting shipping from underwater threats
--capturing/assassinating an enemy leader
--finding enemy spies/saboteurs
--inspiring neutrals or friendlies to keep fighting
--bribing/persuading enemy subjects to turn against them
--fighing in extreme environments and seasons (Russo-Finnish winter, anyone?)
...and so on.
I've got a broad outline for heroic tier so far, some ideas for paragon, and am fishing for ideas for epic.