Neth answers pretty quickly, and this issue goes almost directly back to the issue of communication between players and CMs. The CMs feel they have a lot more freedom to post on silly threads, obviously, and so they do it more. But when talking about "serious" issues (or maybe just more touchy subjects), their words carry more weight, and so they have to pick and choose what they say.
And to that, I have to agree with Tolki, who posts in the thread that we'd rather have an Oprah than a Tony Snow. Sure, things didn't work out so well the last time a CM was completely honest with us, but surely there's a middle ground. BlizzCast is a start-- maybe the devs and CMs should work together to make sure that fairly often (once a week or even once a day), they can speak out on a "serious" issue, and give the player base something to chew on. It could be argued that the CMs' words carry so much weight on serious issues because we almost never hear from them, and if that's true, a regular schedule of discussions with either CMs or devs would help give the CMs more freedom to be more honest with us about what they think about (hey heeeeyy) what's really going on in game.