Big companies have a habit of letting their employees browse the official forums and respond to customer complaints. This is particularly noticeable during heavy patching periods in order to gather customer grievances. And there's nothing wrong with that! The occasional "we intend to change X and Y, but Z is fine for us" never hurt anyone. But having any employees posting around like old chums to the forum regulars can give your company a rather lax appearance.
Companies that successfully pull this trick off often have a huge corporate image and a black-hearted CEO that feasts nightly on the blood of other companies' employees (mostly the ones who post on forums), so they can get away with playing both sides: the big company doing anything for a buck, and the little dev who cares oh-so-much about his pet project and will post on the forums to tell you he's working night and day to make it better! And I bet they're both telling the truth, since there's a correlation between good games and making money.
A company who doesn't have a large image runs the risk of appearing like time-wasters, whiners, and of catering to the vocal minority. You could also give away too much information about upcoming features or say something offensive if you don't have a good PR team to check over posts.
Remember: "I'll give this game a second chance because a dev posted on the forums apologizing for the flaws of the game" doesn't last much further than "my class is weak and all my spells are bugged!"
- If you're a small company, pretend to be a big company. Release your patch notes and figures via huge press releases pushed to all the gaming sites.
- If you're a big company, pretend to be a small company. Let little bits of information leak here or there, and the gaming sites will pick up on it without your help.