Wow last week topped the 9 million ACTIVE account mark. They own around 74% of the global MMO market share, and are still growing. TBC hasnt even been released in asia yet, and that sold over 2.4 million copoes in its first 24 hours on the stands in the US and Europe.
I have beta tested alot of MMO's, from Vanguard, LOTRO, 9Dragons, and others with which I am still under NDA agreements, and I have to say that while some of them are better in some areas than WOW, WOW is still the most polished MMO on the market. Nothing that is currently out there comes close to beating it, and from the rumors concerning further expansions, it will only get better.
On a side not, be careful of the anti-wow crowd. They will have you believe that wow is full of kiddies, and l33t spking pwnzors, and that the game is a mindless grind - they do this to try and create a air of superiority, and make them selves seem for "uber2 etc - its all rubbish - WOW still blows away the competition.
Vanguard was toted as the next WOW killer - a more intelligent, superior game that would address all of wow's weaknesses etc - "Brad's Big Dream" - it went live with over 2.5 million signups - today they are merging servers beceause they have 50 000 active accounts, and sigil has been bought out by the devil (SOE - Brads old company LOL). And their forums are full of a bunch of self obsessed, "VanBois" trying to make themselves feel better about supporting a dead game - one which even microsoft bailed out of after spedning 300 million.
People continualy knock wow, but it keeps growing and people are still having fun with it! It will be around for a long time to come!