From StarWars.com:
"This first of a four-part series launching this week in commemoration of the premiere Celebration opens with Lucasfilm's Steve Sansweet formally introducing fans to the first Celebration event (as well as casting some blame on the dark side for the weekend's wet weather). Sansweet then introduces the first presentation, a Q&A with Episode I creature effects supervisor Nick Dudman.

In addition to Episode I, Dudman had also been involved with creature and make-up effects in The Empire Strikes Back, Return of the Jedi, and later, Attack of the Clones..."

Check out the above link for an audio clip of the 13-minute presentation