When the show started (Back in '94-'95) it was a relatively small event for the press and (small) developers trying to show the big publishers (Nintendo, and Sega at the time) their game or app. E3 eventually grew out of control, it went from ultra exclusive to letting anyone in. Hell, I could have gotten in since I run this "Gaming" blog.
Nex-Gen.biz has this to say today:
According to the Wall Street Journal, Lowenstein said that next year's event is tentatively titled the E3 Media Festival, and will have a target attendance of 5,000. To put that into perspective, E3 2006 drew 60,000 attendees--and that number was down from 70,000 in 2005. In addition, the event will move from its traditional May dates to sometime in July next year, and take place in suites and conference rooms in two L.A. hotels. E3 has normally been held in the enormous Los Angeles Convention Center.