7.7 million users that are active is still pretty incredible after 9 years.
The MMORPG genre has changed over the years and maybe they are seeing a decline in playerbase because of all the new MOBA style genres that are free to play, they seem to be really picking up popularity. League of Legends, HoN, Dota 2. I have a lot of friends that have migrated from MMORPG games to go play these titles.
I'm pretty sure the number of people that play these games has done nothing but steadily increase over the past couple of years (mostly in league, as Dota 2 is still in beta and HoN has only seen a minor increase in the playerbase).
What's next? MOBA-RCE xD Where winning your lane is more important than ever!
Yeah, and meanwhile some entropians would like to see EU subscription based
However it's not lack of f2p that hurts WoW. I know a lot of people who play(ed) WoW from the very beginning and stopped recently or about to stop, because they lost perspective and got bored. Sure, they regularly get new content updates with rich storylines and all that, but after so much years it all started feeling the same (it never was a problem for EU, because while people whine about lack of storyline, most probably would still play even if all mobs were replaced with boxes... mm, wait, aren't miners already do exactly that ).
The only factor that keeps people is the community, but the more people leave the less this factor matters. The most dedicated people switch servers (non-single, unlike EU, world doesn't help too), search for new clans and parties but end up alone again, thinking about leaving themselves.
But unfortunately this all doesn't matter for EU, because all those people I know already tried it and ran away screaming