I'm calling Locke in the coffin. He's my favorite character, but it couldn't be any more obvious that the show's producers hate him. Maybe Terry O'Quinn did something to piss them off - like stealing some of the spotlight away from Jack early on in the series. So, killing him would free up more screen time for their stroke-fantasy-boy Jack (seriously, you should hear the way they talk about him on the official LOST podcast), and now that Ben has become the breakout antagonist character they don't really need Locke anymore.