I think a game like an RTS but focused solely on tactics and logistics ( i mean the fun parts of logistics ), eg set with you as a commander and coordinator of a campaign. you are given resources in the beginning and have to collect all your information yourself, eg by specifically ordering deployment of recon, etc. using this info you deploy ur resources. If you reach an engagement of particular largeness you can command it RTS style, but otherwise it is on a much larger map, in real-time. You can choose totally what your specific objectives are, and you have a 3 or more level detail of the campaign; global, ie everything you've got in vague, then a median level of control, which would be coordinating troop bodies the size of platoons, and then a local control, perhaps with a god-camera controlling squads, like the infared cam in the blomkamp shorts. you could integrate it very nicely into the beginning of Halo 3 - you start as perhaps Hood or an equivalent, who has to recover and redeploy scattered forces using some pelicans&albatrosses. You can make desisions on what resources are top priority - do you secure an armour depot or recover loads of ground troops? As ur resources grow, you begin to make higher-level command decisions - do you hold an underground base like the start of Halo 3 or keep mobile, and offensive?
I would also like to see a really flexible mission planner thing, where perhaps you have a fairly unspecific objective (recover some intel, or somethinhg) and some ground troops with peli/hornet backup to organise and coordinate. u issue orders, and watch the outcome in realtime. if it goes wrong/ u see a fault, you reissue orders in real-time and try to reorder/recover your assault. of course, the AI needed to do that would be pretty hefty...
BTW, ares, like ur avatar