There is a site called GameDreamZ, which has been mentioned here and there recently, and apparently allows people to post things they think they know and have other people, who may or may not know anything but have a functional email address, vote on whether or not the poster knows anything, and if the post gets enough votes, it becomes news.

Someone calling themselves HELLSINMAKER has posted on this site that a full-scale media blitz for Halo 2 is due in January, as well as some other tidbits that may or may not be true:

• Halo 2 may feature a battle over a meteor or possibly a moon
• Halo 2 may have a battle that takes place at a city in the desert
• Halo 2 may have heretofore unmentioned features that are top secret
• There may be new Halo 2 movies and screenshots featuring single and multiplayer action in January

You heard it there first.