I wanna see a FPS mixed with a Realtime strategy game set in the period of one of the early american wars. Preferably the Reveloution or the Civil War. So for example, you could take the position of General Lee and move your troops around to position them in strategic locations.. arrange supply lines.. mount offensives.. things like that. But when an actual scirmish breaks out.. it should let you take control of one of the soldiers on the battlefeild and take an active hand in the down & dirty fighting. When your character dies, you should be able to have the option to switch to another character or even do so at random to check on the status of your different regements & platoons.
Now THAT sounds fun to me.