If a student knows they are college bound, taking a year off after high school would be a great opportunity to figure out what they want to study. An optimum situation, for students who can afford it, would be to take the opportunity to travel and be exposed to the world of which they are a part. This would help them discover more about what they want to do with their lives.
I personally feel as though college is far too expensive. Even some community colleges ask for an entire year's wages from a full-time job. If young adults miss the opportunity to save up money prior to college, they'll have more trouble getting into a college due to loans. I believe students should wait a minimum of one year before they decide to start paying for college.