For those who don't hear today, do not panic. Some folks hear early, others hear late.
Also, we say this every year, but it's true and thus bears repeating: NASS is a RECRUITING TOOL. The primary goal is to provide exposure to USNA to young men and women who come from schools or areas of the country where USNA is not well known or where not many have attended USNA. Even if the person who attends NASS isn't super qualified, the hope is that he/she will have a great time and go back to his/her community and talk up USNA, thus encouraging others to look into the school. As a result, the "most qualified" folks (who may come from areas/schools that historically do very well with USNA) may not be accepted to NASS while someone with "lesser" qualifications is.
As difficult as it may seem, if you're not accepted to NASS, do not despair. You may still have an excellent shot at USNA -- most successful candidates did not do NASS. Also, if you are turned down for NASS, consider requesting a CVW this spring (when they target juniors) as that is an equally beneficial experience.