WoW was a fluke. IMHO poorly designed game - phat lewt grind - and I lost interest within 2 days.
I won't pay by-the-month for a game. MMO or not - Blizzard seems to have done very well w/ games like Starcraft, Warcraft, and Diablo. Why Pay by the month, anyway?
Not even a Fallout MMORPG will...