I believe you have to already have a job in the game industry to attend E3. They've become less restrictive than in previous years but I'm not sure if tickets to the general public available. Good luck!
I am a little disappointed that the gels were introduced so late into the game, but it's not a major complaint. Besides, the modding community recently made those Portal 2 E3 levels which I remember used the gels in some crazy ways.