Yes, My middle school advisor told me that repeat applicants, especially repeat waitlisters have a very strong chance of getting in the next year. This was true for me as I was waitlisted my first time and accepted the second time at Middlesex. I also have many friends who were waitlisted at Andover their first year and accepted the second time around.
2010 hopeful - I would (after April 10) call the people who interviewed you. Talk to them and ask them to honestly give you feedback on your application. Certainly if your scores and grades are waaaayyy below what they would consider, you should target different schools - why waste the time and application fees? However, they might just say they wanted to see a little more growth in one area or a little more progress in another or your essay.... And you could work on that.
""Of course you should apply again! Tons of people get rejected the first year and accepted the second. It shows that you are interested and big enough to try again. Do it. ""
This also applies to HYPS Colleges.