You know Halo has been ruined when the Chief starts talking in full sentences and wearing a cape... seriously, he has full body armor and he needs a cape? I'm taking down all my Halo posters and turning to the dark side of CoD if 343 doesn't put away that stupid owl from the E3 trailer and do something about how lame the Chief is getting.
In order for the halo story to move forward, 343 needs to stop focussing entirely on the Chief's relationship with Cortana and more on the new tech that the Forerunners are bringing to the table. In Halo 4 we learned what some of their weaponry, combatants, and story was; but Halo 5 needs to push into what happened to them and how humans tie into it all.
343 must also touch onto some of the books that have been written to support the story, including the story behind Jul Madama and the events back on the Elite home world of Sanghelios with the Arbiter.
However, 343's first and foremost priority is taking down all the drama with the Chief a notch. They have to think about their audience and I really don't think the current Halo audience is going to appreciate a tear fest about the Chief and Cortana. If they don't correct the Chief's new path, 343 is going to lose a lot more than the Chief's identity; they're going to lose their loyal community. Starting with me.