I think I would find these features tremendously useful.
Ability to delete other peoples posts off a campaign (do I have to ask people to delete their posts before I kick them for not showing up?) would allow for the board to be kept a little more manageable as opposed to an ever growing list of posts (ability to archive posts might be useful as well).
Polls would be very useful as well IMHO, since a GM could just put up a new poll every week saying "Think you'll be able to make it next week?" so that a day or two before the session, they can get an idea of attendance. Voting for peer nominated XP would be a great way to get players involved in selecting who did the best roleplaying in a given session etc.
These features, while not specifically part of the VTT, might be worthy additions. While I don't really think that I personally would make a account on some other service(s) to supplement roll20's features, I would definitely use them if they were available.
