Xbox 360 and Playstation 3 Announcements before E3

So why the heck is there a E3 show in the first place, if they biggest announcements for this years E3 are already happening before?

Gamesindustry.biz reports that Sony will present the PS3 on a sound stage in Sony Pictures' complex in Culver City, just outside Los Angeles, at 15.00 PST on Monday, May 16th.
Microsoft will show their Xbox 360 three hours later (smart move by Sony) in downtown Los Angeles.
At least both announcements are in the area of LA where the E3 is. So I guess several journalists have to change hotel reservations and fly in Sunday the 15th to cover those two announcements ahead of the E3 Expo, which starts on May 18th.
More details on GamesIndustry.biz.

Update: I4U reader Shane M. raises a valid point that pre-show announcements are common. On the other hand these are the biggest announcements since the PS2 and XBox introductions. The challenge for the press is to get both events covered. Most likely they have to work with two teams.

Update 04/11/05:
Microsoft unveils Xbox 360 on MTV!