Sadly, the value of most conference panels is questionable, due mostly to the lack of effective moderation.
Just recently I heard that one nervous moderator asked the panelists to introduce themselves, then went directly to Q&A, providing little structured value to the audience.
On the complete opposite end, I've seen a self-important moderator answer questions from the crowd when it was his job to field questions to the panelists.
Below, I provide some thoughts on how to successfully moderate a conference panel.
Objectives and Approach
Think of the audience as your customers
Treat the audience like your customers; they've paid with money and time to come to your panel. Your job is to give them the information they need, or to entertain them, and often both.
You've one of the most difficult jobs, as you'll have to set the pace, maintain some control, but know when to back off. Remember that you're here to serve the audience first and panelists second.