Halo 4 ended up being a solid effort on 343 Industries part, though perhaps not the homerun Bungie fans really wanted. It's okay though, we thought, it's only the first game in the "Reclaimer" trilogy so they'll be ramping things up from here on out. Not the case anymore, as a Microsoft representative has now said that the Reclaimer trilogy is now more of a saga. Oh dear, this doesn't sound good at all.
"While we originally said trilogy, we've actually expanded this to more of a saga, so we don't want to limit the Reclaimer story within a trilogy."
When a Microsoft representative is telling the public to stop talking about a trilogy and instead about a saga that says one thing to me: this was a business decision and not a creative one. It tells me that Microsoft has plans right now for more than three Halo games, but seeing as most companies don't project too many years in the future, it tells me they want to release Halo titles faster. Are we perhaps looking at yearly Halo release from multiple studios a la Call of Duty.
Mostly, however, it tells me that the creative direction of the Halo franchise has become a tenuous, malleable things. Everything above is speculation, to be sure, but there's no arguing that if changes are being made at all to what was originally planned for the franchise, it's worth being worried over for Halo fans. Maybe the series will get better, maybe not, but this is a story that deserves more than just a single sentence said offhandedly by a Microsoft representative.