The closed minded toward a move to Freemium models for MMOs are simply ignoring the market data.
One simple summarized example of market data (there are many if you actually care to seek and understand):
If WoW launched today, in this marketplace, it is extremely likely they would not only see the attrition curves that SWTOR and Rift (yes folks both games have almost identical subscription attrition curves since launch) but that Blizzard would also pursue a Freemium model early in the life of the game, if not at launch. The only thing that insulates WoW from the market forces right now is the "invested player base". By invested player base I mean the large number of players with years of time and progress invested into the game who simply won't abandon it. They do sub/unsub with each expansion cycle though.
Further, WoW could still succumb to pressure to convert to Freemium. Setting aside their Asian accounts (which number ~ 6-7M and never were subscriptions, they are token based pay-2-access) the US/EU subscriber based has suffered 2M losses over the last 12 months (which is ~ 40% of their paid subscription base). Once their panda expansion cycles the subscriber base, then the real pressure for them begins.