Arbiter's had more than just shoutbox moderation powers... and with some more site/forum integration planned, there might be additional abilities given to them.
Promotions are obviously going to continue. In fact, they have continued. Knowlee was just recently promoted.
At the moment we are holding off until vBulletin 4.0 goes Gold. (It is still in Beta form). Once that's out of the way, we will be reskinning the forums to more so resemble that of the site. That's still a bit down the line, perhaps another 2-4 weeks, who knows.