Azu

Instead of changing WoW, why not just nip the problem in the bud? Have there be a bunch of bots that simulate players, and voila, there's your single player version. If you make a decent chat AI for them it could be pretty fun. Obviously they should be generated with fairly randomized attributes so they aren't all the same. Also it would probably be good to have their data save instead of them all starting fresh over and over. This way it would be more realistic since you could make friends. Then it will have all the pluses of being an MMORPG, but it will be a single player game