Last year was the last time they had E3 as we know it. The organizers folded the tent and E3 has been remade into a smaller event open only to people in the industry and press. It lasts for only three days and runs from July 11 - 13.
Check out the Penny Arcade Expo. It sounds like it will be more like the E3 of the past. There is also the Tokyo Game Show and the smaller shows like MS's X07.