This is something that has been proposed before... Just an icon before a thread with a post from someone from Stardock (with a link to the post?) would already be a nice improvement, that's something I really like about the Blizzard forums. You can see at a glance which posts might contain some new / official info.

Something like this isn't really technically possible (not without an inordinate amount of work, anyway) until we get proper usergroups implemented in the forums. Which is on Bara's todo list, though I couldn't say how soon.