This is a tough thing. Mike Munchak seems to be a really good dude. The players obviously really liked playing for him, but he isn't cut out to be an NFL head coach. He will land on his feet because there is no doubt that he is a great offensive line coach.
This was just the right call by Tommy Smith. Munchak did improve the team this year, but they were always going to be stuck in a cycle of mediocrity as long as he was the coach. Smith obviously believe that.
There are still a lot of questions that need to be answered. Will they cut Chris Johnson? Will they draft a quarterback early?
Those will be answered in time. For now we know that the Titans are in the market for a new head coach. It is an exciting time. They are not that far away from being a good team, but this hire is crucial. Get it right, Ruston/Tommy!