The Fortnite ones will probably be the most interesting.
Source: http://epicgames.com/news/epic-games-announces-plans-for-game-developers-conference-2013/Epic said:Sharing Ideas and Expertise
Continuing with tradition, Epic will support GDC with lecturers, panelists, bootcamp hosts and more. Confirmed speakers include the following members of Epics team.
Billy Bramer, Gameplay Programmer, Under Construction: Crafting Fortnites Building System
Jim Brown, Lead Level Designer, AAA Level Design in a Day Bootcamp
Laura Fryer, General Manager (Seattle), Producer Bootcamp and The 3 Most Important Ingredients to Making Great Games: Motivation, Motivation, and Motivation!
Wyeth Johnson, Art Director, Killer Portfolio or Portfolio Killer: Part 1 - Advice from Industry Artists and Killer Portfolio or Portfolio Killer: Part 2 - Portfolio Review
Kevin Johnstone, Senior Environment Artist, Subtracting to Add: Environment Optimization Techniques, Killer Portfolio or Portfolio Killer: Part 1 - Advice from Industry Artists and Killer Portfolio or Portfolio Killer: Part 2 - Portfolio Review
Bert Lewis, Lead Character Artist (ChAIR), Designing the 100+ Characters of Infinity Blade: Establishing Constrained Diversity
Jonathan Lindquist, Technical Artist, The Inner Workings of Fortnites Shader Based Procedural Animations
Chris Mielke, Producer, Building Epic Worlds through the Strengths of Artsourcing
Niklas Smedberg, Senior Engine Programmer, Optimizing AAA Games for Mobile Platforms (ARM theater, South #1124, Wednesday, March 27, 10:30 a.m.)