Apparently, some guy’s nephew works for Bungie, and he’s said a few things on the Team Xbox forum about Halo 3, (thanks Kotaku), how much truth there is in what he speaks we really don’t know.
The information, reliable or not, is interesting at least. The dude in question claims there’ll be a “darker and more gritty” plot. The opening of the game is apparently "thousands of years before the timeline of the original Halo: Combat Evolved", apparently (that wasn’t an accidental repetition).
Shaedon, as the “informer” is known as on Team Xbox, claims Bungie are “attempting to maintain an online cooperative component for the campaign supporting more than two players at once” adding that Halo 3 "will have a multiplayer mode which pits players against bots in scenarios that are directly connected to the story of the game". Apparently some maps will be able to cope with an excess of fifty players.
Old maps Zanzibar, Hang Em High and Sidewinder will return albeit "completely reworked. Zanzibar will be mangled and torn apart as though after the battle, the sky will be dark red. Sidewinder will have four legs instead of just two, with bases at each end. Hang Em High will have a massive tree at its center and the structure will be deteriorated."
Shaedon claims “They're attempting to implement both a map editor and a movie maker, which would allow players to send and receive their maps/movies through Xbox Live. This would apparently be on a separate disc, and they have an entire team working just on these two projects.”
The poster admits that he isn’t able to verify any of this; it’s simply what his friend told him, and is taking it all “at face value”.
We haven’t even had Microsoft’s word (fner fner) when exactly the game will come out, but Bill Gates claims it’ll be at exactly the same time the PS3 comes out, which should be next Spring.