Halo 3 on Xbox Live! Grand Theft Auto an Xbox 360 exclusive?

It's a few minutes before the Microsoft E3 press conference, and the fireworks are beginning.

If you head over to TeamXbox.com you'll find two huge nuggets:

• The Halo 3 104 MB trailer is available right now (for free) over Xbox Live!
  UPDATED: And from TeamXbox.com!
• Grand Theft Auto IV for Xbox 360 will hit retail in October 2007, and "Exclusive episodic content updates via Xbox Live are promised". Dunno if just the content will be Xbox 360 exclusive, or if the whole title will.
  UPDATED: It looks like GTA IV will launch on both the PS3 and the Xbox 360. So, no exclusive, but (for the first time), not a Sony exclusive either. No word on the exclusiveness of the Xbox 360 content, though.

Wow, the Sony press conference is already looking tame by comparison, and the official Press Conference hasn't even started ...