Wow, thanks guys. I was kind of worried my huge post would scare everyone away, but thanks for taking your time to give great answers!

A few more points I want to make:
The game is intended as an online/mp game. Right now, we're working on a smaller "sandbox" version, which will basically be a large demo of what we have in planning. Our real goal is to eventually turn this into an MMO (I know, don't laugh, lol), but only after we've expanded our team and acquired all the needed software/resources. We know we CAN do it, it's just a matter or being able to build an adequate team and finance development.
That being said, the final retail version wouldn't have things like AI infantry. However, there will most likely be AI machinegun nests, anti-tank guns, supply convoys, and probably ships.
We also plan to have a limited supply system. It's going to be broken down like real militaries, with a high command structure and the whole nine (run by players). Combat units will have a limited number of men and equipment. The point of the game will be an eventual domination of the map, via capturing cities, key positions, chokepoints, etc. Ok, well I don't want to reveal too much of the surprise, lol.
Basically, it's going to start fairly small. We'll do all we can, and just continue to patch in new content and features once things get rolling.
I agree though, we don't want to be 100% in either direction (sim or arcade). That narrows down the market a lot. However, I'd like to stay a step on the "simmy" side of things. Arcade-style gamers will go ahead and learn to play if the game isn't ridiculously difficult. Simmers, however, won't take anything "arcadish" seriously, and would be immediately turned off. I'm the same way.
I want to keep the equipment performance (i.e., tanks, guns, etc) as close to 100% accurate as possible. However, we don't want to expose players to all the true boredom of combat. Soldiers often sat around smoking cigarettes for hours, days, weeks, before they ever saw a fight. We have to cut those dull moments out and create an action packed war. But that's easy enough. Players can just "hop" to the area the battles are going on, jump in, and fight. They don't have to sit around and play cards in the barracks!
