Based on the interviews with George RR Martin and Peter Dinklage that I have read or seen, I would expect this event to be both very entertaining and very interesting. Of course, it could also be loaded with some major spoilers for upcoming stories for all those who haven't read the books - especially when things get opened up for questions from the (let's assume completely obsessive) audience. Are you willing to take the chance?!
Is so, you can register your interest
here.