It seems like the time is ripe for change.
You know, I can see where a lot of large, multiplatform third parties like EA would not be that interested in E3 anymore - from the press's point of view, the show tends to be all about the big announcements from Microsoft, Sony and Nintendo, followed by shifts in big exclusives, like Grand Theft Auto on 360 and the Dragon Quest spin-off for Wii. Nobody cares much about a new game that's coming to all consoles. Off the top of my head, Rayman was the only multiplatform title that seemed to make an impression this year. Madden sells exteremely well every year, but I doubt E3 does anything for it. Games like Spore probably get better coverage out of the Game Developer's Conference than E3.
I hope this doesn't hurt PGC, but at the same time I'd have to say that an invitation-only type conference might make more sense, so the media can cover the games more easily and the exhibitors don't have to spend as much money.