WW1 might be a bit boring. You wouldn't have the weapon and vehicle diversity that exists today.
Perhaps something like a Lt. Dan family history thing would be cool. For those of you who aren't familiar with the Forest Gump character, Lt. Dan had a familly member involved in every american war and died in combat. I might be kind of cool to have each map and part of the campaign set in a different war. WW1, WW2, Korea, Vietnam, Gulf war and Afganistan. I doubt they would do that however