whismerhill you are comparing apples with oranges.
multiplayer in a turn based strategy game versus a MMORPG with a large PvP focus? c'mon, lol!
and Bethesda and TESIV is just another example how a developer can piss of their loyal fans and costumers, 3 useless additions for $$ when alot of people have been waiting for a much needed patch over a month now (especially for the non-english Oblivion versions. the german one is totally fubar).
Bioware and NWN for the win in that regard (crapload of patches, huge amount of new content and enhancements for free, and alot more content / $ with premium modules too than what Bethesda is doing).
I dont see any difficulties in adding multiplayer to GC2 unless the games infrastructure is designed badly in the first place (e.g. too many things hardcoded). players take the spots of some of the AIs. so what? if the AI is that independent and flexible as advertised it shouldnt have any effect. and what balance issues are there? every player AI or human has the same possibilities and options from the start aside from race bonuses. all you need is to figure out in what ways the action of AI and players are stored and forwarded to each other and if it should be strictly turn based or simultanous in some regards. then just make sure the Diplomacy skill works between players too (e.g. can only trade money/techs etc if the one with the lower diplomacy skill adds more to the bargain) and allow for ship designing outside the game or prior to the game so during the game you only add weapons and stuff and not work on the visual side of ships while the other players are waiting. but all in all those are just minor considerations. I dont see any reason the game needs to work much if any different at all multiplayer versus singleplayer.
if thats so hard then I suggest getting better programmers.