With the 2012-13 season more than halfway over, the majority of NBA coaches don't have to worry about their job security. And even those who are concerned should rest easy for the most part.
Making a change behind the bench now would be pretty inconsequential for those teams that are debating a move: Having to install a new system this late in the game could be more counterproductive than anything. The smart money says that we've already seen all of the firings that we'll get in the NBA this season. That said, there are a few coaches who might be on the way out if their respective teams completely pack it in over the next few weeks.