Online registration will end this Wednesday, June 9, at 11PM Pacific (a.k.a. June 10 at 2AM ET).
This is the first time E3 online registration has ever been shut down prior to the start of the event. The ESA, which runs E3, explained that the measure is being taken this year because registered attendance is close to hitting the limit. The organization expects between 41,000 and 45,000 industry professionals, analysts, journalists and retailers (and probably a few impostors) to attend.
Qualified industry professionals can still purchase badges on site, but that involves things like ... lines, ewwww.