Bump.
Not to be a pest, but I'd really love to see the campaign comment section expanded out into a full, multi-topic forum system. One thing I love to do in my online games is to keep the action going, so to speak, between live sessions.
A good forum system can be used to keep up-to-date character sheets, host player discussions on where to go and what to do next in sandbox-style games, divide up treasure, and address single player activities, such as when the party rogue wants to run around at night robbing stores, without having to do all of that during your preciously short live game time.
Just to take it a step further and really make it a Roll20 thing, you could make it so the forums could link to the tabletop and vice versa. For example, a forum post could link right to a game handout, or a forum topic could automatically be generated during the game by the GM.
Perhaps the best way to really own the forum system as a Roll20 exclusive would be to add dice mechanics in a special display along with each post. Maybe you could even link it to the reply system, so the GM could post a topic like "there's a locked door" and each player could reply to that topic with a roll, along with a post like "I force the door" or "I try to pick the lock."