The news of the Broncos firing Nathaniel Hackett shouldn't have been surprising to anyone. The only question was whether the Broncos would move on from Hackett before the end of their season or very soon after their season ended. Yesterday's horrific performance by the Broncos against an injury depleted LA Rams team, coupled with the internal and external fights that took place with the Broncos, was the final straw for Hackett as Broncos HC.
My guess is the Broncos will attempt to hire Sean Payton as their next HC. If Payton elects not to become Broncos HC, another experienced NFL HC is likely. Cowboys DC Dan Quinn, who was amongst the Broncos finalists for the job last winter, probably is heavily in the mix for the job this winter.