Don't forget the lightning talks .
For a small audience (yes, 300 persons is a small audience) the schedule should be carefully done, probably the rooms should be divide by intended audience (developers/power users/users...), instead of the usual themes/areas (desktop/multimedia...).
We can't make everyone happy, but trying to avoid very related presentations at the same time should be a good start, people usually get pissed when they have two presentations at the same time, that they like to attend. As participants, some of you already experienced that situation for sure .
About the call for papers, I don't know the amount of submissions that you are expecting, but agree that the wiki isn't the best option to organize it. How was it done in the 2008 summit ?