Despite being some four years old, the userbase of Blizzard's World of Warcraft continues to grow, if only at a so-so rate. One of the game's lead designers said as much at the Games Convention, allaying fears (well, message board banter) that maybe, just maybe, interest in the game had peaked.
The game had some 10 million subscribers as of last January.
Now, that may not be completely indicative of how many people actively play the game—I keep paying for my account but seldom actually play—but that doesn't much matter to Blizzard. As long as you're paying your $15 a month, Blizzard's as happy as an Orc in Orgrimmar.
And who knows what'll happen when Wrath of the Lich King comes out. I imagine there will be folks who buy it, install it, and play for like an hour then let the account continue to collect dust. That's my plan.