I had once thought of a multiplayer game idea with one attacker and one defender. The defender would have a base to defend, and must try to stay alive as long as possible. The attacker could drop reinforcements on the map to try and storm the other person's base. The location and types of units would somehow be selected by the attacker, so the defender couldn't just reinforce all their entry points and make it hopeless. I was thinking it'd be cool to add in game menus to select where you wanted reinforcements, and what kinds. But, I don't really know how to code something like that. The idea came to me after seeing some code that appeared to control the menu in game when you selected units, but I never really did have the time to figure it out, and the idea would require so much work anyways that I just never bothered.
So yeah, not quite the same ideas as yours Whiteclaw, but sort of similar.
I suspect these ideas would be easier to do (especially adding AI into arbitrary levels), if we decided to rewrite the game or something. It's a little hard to work with the current interface to build a decent AI. Well, actually, it's hard under any circumstances really, but it's especially hard with the current setup.