1> This might not be Onyx or any shield world but a completely separate installation. Could be that what the good doctor and the Spartans found at Onyx was a gateway to the actual Shield world. Which was in a completely different location. All the so called shield worlds could be gateways to the same place. And Chief was heading to the actual thing.

2> If this is actually a shield world then all I can say is there are loads of Sentinels who would treat the chief hostile (remember in Onyx the Spartans had a nice party with them). This would definitely mean that in the next game Chief has a lot of clean up to do… Lots of actions with big guns(I hope)!!!

The Forerunner only fully operate in the background and the past-tense; it is impossible to have them play in the forefront of a story’s events. As for the Forerunner planetoid and the FoD’s floating shell, it is likely that that is it. There is nothing more to tell. Since this is the end of Master Chief’s story, and given that we were first introduced to the Halo universe via his story, the meaning will be clear.

The story began with him, and it ends with him. Halo Wars, Halo 3: ODST, and other coming products only fill in the blanks of past events, and that means events and characters that have chronologically been played out. That is probably what Bungie meant by other story and character arcs; filling out the holes in the story.

But that also means of course that there is nothing after these past events and the trilogy. Halo 3 ends the entire story, and the FoD’s shell floating towards an unknown planetoid is a perpetual mystery, never to be solved.

As the “Art of Halo 3″ says about the end on pg.115;

“The implications here are clear, the Chief’s story concludes where it began-in a cryo chamber. His duties completed, his mission achieved, the Spartan rests. Cortana and the Chief are adrift in space, a time capsule and ultimate representatives of humankind’s achievements.”

In other words, they are going to be nothing more than artifacts, representatives of humanity, heading towards some never-to-determined, empty and worthless Forerunner facility. Their previous trilogy, Marathon, had an open ending with no true resolution, so it should be an almost certainty that this will be the same.

After all, if they leave it open ended, it saves them the effort of actually truly answering any of these questions. They like vague, and sometimes lazy storytelling, and the desire for open-ended interpretations and endings is a perfect cover for writer laziness.