VGChartz tracks data by week, counting only US Physical Pre-Orders. If you start on this weekend http://www.vgchartz.com/preorders/40762/USA/, the first where you can see data on SWTOR pre orders ending Aug-6, there are 203,000 physical US pre orders.
Now you can scroll right using the arrows by the week listing, and notice the change in pre orders. Assuming that digital+Euro orders all increase at the same rate, you can go ahead and speculate when you'll get in.
They ended around the 27th of July, im assuming the heaviest pre order period was just done, so around 100-150k were invited.
Listening to http://www.swtor.com/community/showpost.php?p=66561&postcount=6438you can see they plan to invite AT least the same amount of people tomorrow probably more. So I'd scroll to where pre orders = 300k, and if you ordered before that weekend date, you may have a chance for tomorrow, if not, hang tight.
I'm guessing they push to the 400k mark, mid september pre orders, you can see the first few weeks you scroll through are around the 20-30k increase per week, so they can invite a group spanning a longer time frame. Whereas if you ordered end of Oct-December, some weeks increase by 70k+, so smaller time frames will be let in.
Now please, do some math in your brain, speculate for yourself with some educated guesses, and let it give you peace enough to relax and not flame the devs while you are anxious. GL to all, I'm a pre order on 29th of Sept, so if they dont pass the 430k physical pre order mark tomorrow, im out of luck till the next day most likely.
EDIT: Think in PERCENTAGES people, the exact numbers don't matter, and just assume euro/digital orders increased at the same rate as physical preorders, because they probably did.
EXAMPLE:Guessing we hit the 150k mark on the site stats with the first day of early access. 150k is about 16% of the total number on that site. So say 16% of the actual number got let in on first day. Say they try 25% tomorrow, 25% is 235,000 of the 940,000 total number on that site. 235,000 second day + 150,000 first day = 385,000 mark, now find where that is for weekends by scrolling over.
My prediction, all those ordered up to 10th of September get in tomorrow off that data. Bet I'm close.
Some quick data:
Total Physical US Pre Orders: 939,358
Guestimated end date of invites for first day: July 27/28
Larger load granted tomorrow + following day
http://www.vgchartz.com/article/88591/usa-preorders-chart-10-december-2011-old-republic-nears-1-million/ Someone should write the data points and make a full sized chart and link it, <3