Sig,
As someone who recently decided to split too, I can tell you that I waited until the last minute to tell the bosses. There are WAY too many 179 day non-flying TDYs to Iraq that you would get on the "short list" for. As much as it sounds like retribution, it kinda makes sense...let me explain: You say "you're done" and leaving the service and Johnny is staying in (to the bosses knowledge) who gets sent on these deals? You guessed it, the guy that has already decided to leave. Giving a guy that says he's leaving does no harm in their eyes (Bosses thoughts: What's he going to do get out? He already is.) For this reason alone be careful and make doggone sure that you are committed to the decision you make!
Philly