well i remember originaly CA were gonna make STW have a online and LAN multiplayer campaign, (i've got a PC Gamer with a preview in it) it was fairly well thought out but gameplay would probably be terrible like Heroes of Might & Magic, turnbased and takes 6 weeks to finish a game. due to the complexity of the total war games it would also require a fast DS so you would have the same problem as the more complex half-life mods. also most people can't finish a normal game of MTW in one sitting so against real people it would go ten times as long and you would have the HOM&M problem of time. it would be good on LAN, but not online.
Thanks dessa