I'm wondering the same thing! I read in someone's recent TR that the boarding process had changed!! It was not first come - first serve. If I understand correctly, you are given a random category number - You may receive a 3 while the next party in line may receive a 4 or 5 . When boarding begins they call your number (and also from what I understand - the speaker system is not loud enough, so most can not hear their number called) and those who have that number are allowed to board.
I am sooooo hoping I am not correct in this synopsis. Even though you are there first thing in the morning others, that have arrived later, may still board ahead of you.