Another lesson to be learned: don't let this round discourage you. Pull together a new application, and set your mind to the task. There are plenty of young E4 Sailors that I've known (having just finished STA-21 myself, awaiting my transfer to Pensacola) that have been picked up for STA-21.
Some make it on the first shot. Others get picked up after the third or fourth submission. One person I knew in particular got picked up on his third try for NFO, was NPQ'd due to high blood pressure, and reapplied the next year.
What happened to him after he reapplied? He got picked up for core.
I know you're discouraged, probably pretty peeved about it, but if I may offer one suggestion, it's this: don't let the FY11 results hold you back.
Good luck on your next application and I hope you get selected FY12!