The below appears as "The Story So Far" on Halo3.com as of this writing, May 2, 2007. My notes interspersed below in italics.

It is the year 2552.

Humanity has long been at war with the terrifying alien civilization that collectively calls itself the Covenant. This monstrous conglomerate of warlike species sees Humanity as a form of heresy against their religion - a faith based in the single-minded belief that a Great Journey awaits the faithful.

Unfortunately for the galaxy, this "Great Journey" must begin with the firing of a series of ring-like weapons scattered throughout space. These vast, terraformed rings are called Halos, and have been long abandoned by their mysterious ancient creators, the Forerunners.

Still no clue to why Halos were terraformed, if they were simply designed as weapons and Flood containment/study.

This conflict, terrible and destructive thought it is, has been complicated by a series of cascading events. One of these artificial worlds, these Halos, was discovered and subsequently destroyed by Human forces. Led by the last fighting member of the legendary Spartan II military program, Spartan 117 - the Master Chief, a small band of soldiers managed to defy the Covenant and obliterate the Halo installation.

MC again referred to as "last Spartan" despite the existence of other active Spartans in the novels. The site is apparently designed for an audience that may have played one or more Halo games, but hasn't read the novels.

A clash at a second Halo installation became a galaxy-spanning catalyst for destruction as civil war erupted within the Covenant. Driven by revelations that the Covenant leadership, the Prophets, had been deliberately deceiving its populace for millenia, the Covenant entered into a brief and complex civil war, and formed new alliances within its ranks. The final result of that conflagration was that the Elites now find themselves allied with humanity.

Solid confirmation of the human-Elite alliance, which was only hinted at in Halo 2. With all the Elites allied with humanity and Brutes not playable characters, it looks like Elites are off the target list for Halo 3, unless you're into friendly fire.

The truth was that these Halos would not take the Covenant on a Great Journey, but rather eradicate all sentient life in the Galaxy. The cataclysmic structures were built by the ancient Forerunners as a last resort defense against the most terrifying menace the Galaxy has ever known - a menace the deluded Covenant has reawakened for the escond time in a hundred thousand years.

Perhaps another clue to the non-Bungie origin of this text, but rather written by a third party with access to Bungie materials that may not have included the novels: while we supposedly know that the Halo array will eradicate all life, we do not know that it doesn't provide a "Great Journey" of some sort; this may refer to the opening of an entrance to a slipspace safe bubble, like that described in Ghosts of Onyx. The Prophet leadership might have mistaken this safety mechanism for the means of the Forerunners' escape from the Halo blast. According to 343 Guilty Spark, the Forerunners did not escape.

That horror is the Flood, a sentient all-consuming parasite that makes monstrous puppets of those it kills. The Flood will not stop until every last thinking creature is abosrbed into its ferociously intelligent plan.

More suggestion that the Flood are incorrigible. If no parley with them is possible, humanity will be forced to choose between Flood absorption and Halo activation. However, for the Flood... what is next? What is their "ferociously intelligent plan"? What would Gravemind do if he achieved his goal of absorbing all intelligent life everywhere in the galaxy? How did such a parasite arise in the first place-- was it engineered for the purpose of storing genetic memories? Some, but most assuredly not all, of these questions will hopefully be answered in Halo 3.

Now, the second Halo has been activated, putting all of the remaining installations in a dangerous state of emergency standby - they are primed to fire.

Worse still, the Covenant has discovered the long-hidden location of Earth. They have crushed almost all human resistance as they seek vital clues to the nature of the Halo array - some of which may have been hidden under our very feet for untold millenia.

Even with our newfound allies, the Elites, and their valiant an honorable leader, the Arbiter, we are still hopelessly outnumbered and at the mercy of the will of the Prophets, and the single minded force of the Flood.

Another confirmation here of something only suspected before; that with the Council Elites murdered, the Arbiter will take up the leadership role. Good thing he killed the Heretic or he might have had competition for the job!

With time running out, all hopes for the Galaxy now lie in the hands of one soldier, Spartan 117 - the Master Chief.

Finish The Fight!