I don't know how people like the expanded universe or the novels, but Halo: Hunters in the Dark was released today.
I'm only roughly 50-60 pages into it, but it's shaping up to be an interesting and worthy novel, after a series of klinkers (IMO).
The basic premise is that a couple of human researchers on Installation 07 (Zeta Halo, aka the Seventh Halo ring) discover a mysterious signal that is shown to be a countdown timer. The same signal is found on the other two located Halos (Gamma Halo and Delta Halo, aka the Third Ring and the Fifth Ring), and is pinpointed from to be coming from the Ark. The UNSC concludes that the signal is a countdown to the remote activation of the Halo Array.The UNSC informs the Elites, and the two send a contingent of Spartans and Elites to the Ark in an attempt to find a way to shut off the countdown, and while there, there is tension and turbulence in the UNSC Spartans and the Elites, while they grow to grudgingly respect each other's help. The novel also serves as an introduction to the last member of Locke's team, Spartan Olympia Vale (though she hasn't appeared in the book yet where I'm at), with Buck having received his own novella explaining what happened to him after we last saw him, and Spartan Holly Tanaka's story being explained in two editions of the Escalation comic.