IGN says that 'sources' have confirmed Halo 3 will be part of Microsoft's E3 Event
. From the article: "The video is allegedly two minutes long, although its contents weren't divulged. We're guessing a wild breathtaking battle on Earth. Knowing Microsoft, the publisher will want to show all real, in-game engine footage to counter Sony's fantastical CG videos from E3 2005. When Microsoft was contacted, the company issued its standard reply, 'We don't comment on speculation and rumors.'"