WoW has a revenue of what? 12 dollars/month = 144 dollars a year, times what? 13 million paying members? That's 1872 million, or 1.9 Billion. Of course, they have some expenses, but I believe they are comparable to the cost of what Activision does; developing entirely new games.

Now, Activision. On current gen games, they have sold around 70 million. The average revenue is, presumably, around 40 dollars. That's 2.8 billion in total. So I'd have to say that lately, Activision is at around 1 billion revenue/year, and Blizzard is at around 2 billion revenue/year.

BUT!

That's wrong. Activision Blizzard has reported a 5 billion in total. How much of that can Blizzard have made? Unless the WoW number is drastically higher,  Blizzard can't have made more than 2.5 Billion, or at least at a top of 3 billion. So it's actually rather close (heck, Activision could be bigger).

Having said that, Blizzard is going to be far larger in 2009 (due to the fact that they actually release games this year), and they probably made more profit overall.