MMORPG's are hopelessly plagued with security problems: if it's not outright hacks, then it's ruthless mindless exploitation of every flaw, glitch, and loophole in the game design. You might say, "Well just carve out your own little corner and avoid all the lamers" but that's pretty tough to do. Impact and fallout from the exploit-minded simply rules the day in every MMORPG and even in standard multiplayer games that run client-server MMORPG style, like Diablo 2 or some of the combat games.
Like it or not, gamers in large enough numbers are not only willing, but eager to cheat the system any way they can, and venturing down that path with the game design is the road to a very hot, brimstone-filled environment. I'd hate to see that happen to Civ.
Standard multiplayer goes that road, too, just not to quite such a hopeless degree that it impinges on those who play for the joy of the game, not the glory of game destructionism. Yet the more complex the game, the more vulnerable it is to security problems and design flaws. That's one reason classic games like chess, go, and backgammon will never go out of style. They allow better for the rigors of competition than do modern, complex video games. The rules are clear, simple, well tested and honed, and have stood the test of time. I've yet to see a modern game that would rate even as Little League, in the competitive environment that sees chess and bridge and go as the major leaguers.
I think Firaxis has shown uncommon dedication to the rules of their game, to prevent it from descending into exploitation to the point of irrelevancy. I imagine they are holding some pretty high standards for what they would release as multiplayer, and are fully cognizant of just how tough it would be to tighten their game up to the point where it can survive in that environment. I would hope they have the sense not to go anywhere near the MMORPG environment. That's the kiss of death for game integrity.
- Sirian