I have a suggestion that I'm sure will be unpopular, but I'll say it anyway:
Take down the forums 4 hours prior to the keynote, during the keynote, and for 4 hours after the keynote. Possibly allow access only to Demi's/Contributors during that time period. Use the lowbandwith version of the site with that awesome coverage system Knox made during those hours to display updates, important information, etc.
If the forums are up, it'll just be like coverage of any other event. 200+ posts asking simple questions that can easily be answered by taking 5 minutes to browse Apple's site, 200+ posts ranting about how stupid the new product(s) is/are, and so on... Maybe taking down the forums for the greater part of the day will eliminate the many pointless threads that end up in the wasteland. Allowing access to only Demi's/Contributor will allow topics with important questions/issues to be raised and discussed before tons of posts asking the same questions can be made.
Just my $.02