According to this story, it is still conceivable that the Missouri legislature will cancel the February 7 presidential primary, but probably the primary will still go ahead.

This instance is one more example of great instability in the 2012 presidential primary season, relating to election administration. As the story mentions, it is possible the primary will be canceled even after candidates have filed for the primary. Presumably the $1,000 filing fee would be returned to each candidate who had paid it, if the primary were canceled.