The following charts come from a post at the official forums:
I figured the community would like to see the above graphs.
"WoW":MoP now has got less subscribers than the TBC peak of 8.2 million...
This is really sad. The only reason the above makes me content is because the more subs MoP lose, the closer Vanilla, TBC and WOTLK Legacy-Progression servers get.
I really miss WoW and I'd love to resub to play original WoW. MoP isn't Warcraft IMO so I don't want to play it.