I like it on the discussion forum, specifically. The shoutbox seems like more of a "quick" discussion type of feature and it doesn't have to clog up or ugly up the rest of the forums by having it on the main page, if it's stuck here above the general discussion forum.
Then again, I honestly do not care. The shoutbox looks nice, so the whole "ugly up" argument is moot. Either way, I'm just glad we now have one!