Personaly, I'd love to see a detailed strategy game where you could control all aspects or delegate what you wanted, have some kind of 'political influence' system in order to get what you wanted, with the option to take control of ships or planes for the naval battles if the player desires, maybe even have a role playing aspect thrown in where you can start as a young and promising commander and work up through the ranks.
Maybe with more and more powerfull computers coming each year it won't be much longer until we get a true 'open ended' WWII game.
I've been waiting for one set in the Star Trek universe for over ten years now also. 
