I was at BlizzCon and saw it first hand. The lines to play Mists of Pandaria were embarrassingly short. You would have thought with the expansion supposedly being the "big" announcement this year, that lines would be hours-long. That wasn't even close to being the case.
And if Blizzard wasn't hemorrhaging subscriptions, why are they bribing WoW players with a free copy of Diablo 3 when they commit to a year of WoW?