@Daedalus
Yes, there are better ways of controlling information. However, there are certain things they cannot control. A big one is what someone else pointed out on this forum: they have to trademark the names of their expansions, and trademark apps are public information. As such, it's very difficult to keep such things a secret. What you CAN do is set up a few false leads to throw the market off (like movie makers who film "Captain America" under a secret name like "A Day by the Lake"). If "Mists of Panderia" turns out to not be the next expansion's name, the playerbase will take future "scoops" about trademark applications with suspicion, and Blizzard has more control over how much buzz they can generate on their upcoming titles. Is this 100% accurate or effective? No. Is it risky? Not terribly. It would even be a little clever. All I'm saying here is, that's another explanation for what this could be. And anyone saying "Nope, this is how they did it before, so now we know 100% that this is the name of the next expansion - let the speculation begin!" is not as sure as they think they are. If Blizzard plants a false lead or two, those uncertanties widen.