With the Game Developers Conference, you pay your money and you take your chances. Most of the seminars are at least salvageable, with some educational or entertainment value.
Other seminars are an hour of your life that you will never, ever get back.
Yesterday, I stumbled into a talk that was humorously titled by its speaker, "Music Licensing for the Jilted Generation." That was the most interesting thing about the talk.
I know nothing about music licensing. And when I left, I knew less than nothing. The man spent ten minutes reading off the features of the PlayStation 3 game SingStar.
The moral of the story: Follow the crowd. If a speaker attracts an audience so small you couldn't even field a baseball team, he's for sure someone you don't want to listen to...