Quoted from VolunteerPin:LE pre-order folks can change to an SE at no cost (if they were paid up at the time of announcement) but I'm not sure if you do if that basically opens up another LE spot (I'd guess so).
You bring up an interesting point... I'm assuming there will be only 1500 LE's (Smaug & Standard LE's). I see many switching #'s when they do. I actually thought most LE's were spoken for. Strange