you can tell from the ending that there's going to be some sort of sequel
but they have also said that the halo trilogy is
over
the halo rings, the flood, and the covenant are done with (as far as we know
)
it's definitely going to have the master chief in it, and I'm guessing kelly, dr. halsey, and the other spartans in Onyx's dyson sphere will play a part; why would they all these characters in books based on a game, but not have some of the most important characters
in the games?
i'm thinking most of the stuff in it's gonna be original, there will be some completely new threat mc's gonna have to take care of.
on the bonus disk that came with the legendary edition (i havent watched it in a while so idk if all this is 100% accurate) if you look in the bestiary or whatever where it's talking about the levels of technological development of certain species, if i remember correctly, the highest level is 5, which is the level the forerunners reach, and at some point in it, it says that no species, to their knowledge, has exceeded their level of advancement except for the "Precursors", and i think it offers some reason as to why they are not considered in the levels of advancement. perhaps the next "game in the Halo universe" (not "Halo 4") is going to have something to do with them; maybe there was something worse than the flood that wiped them out; maybe they are the source of the forerunner's highly advanced level of technology; or maybe they had something to do with the rings and whatnot and the forerunners adapted their technology like the covenant adapted that of the forerunners.
all i know is, it's gonna frikkin awesome and i cant wait to see what in store for cortana and the chief (cheesy, i know :rolleyes )