Was that sarcasm about not much going on at 10 AM on Thursday? I personally like avoiding the dealer hall opening and getting my day started at 8 AM running or playing in an RPG. 

I may hit the hall at 10:30 just to avoid the huge rush and because I don't care about "we only brought 20 of this hot new widget that you can buy at a discount in a month or two at home anyways" exclusives. Seriously, we have good local game stores and the internet now, it isn't 1988 anymore. Unless I absolutely have to buy it right then and there why lug it around all day? 

In past years many companies that have offered convention exclusives have also offered them through their web store that weekend too- that way all of their fans in other countries can buy goodies too. I have literally bought my Gen Con exclusives from my hotel room and had them just shipped to my house a couple of times in the past year.

I will say that I try to get whatever I need to get done in the exhibit hall done on Thursday so I never have to go back to that area again. The crowds just get more ridiculous as the con goes on, more and more cosplayers start showing up and clogging the walkways, and (Ye Gods, WHY????) more and more people start thinking that pushing a baby stroller down the aisles in the exhibit hall is a good idea.

Sadly, the dangers of fat guys wearing huge backpacks who are completely oblivious to who and what they are hitting with their backpacks never ceases.

Gharris, mind you I am not one of those people, but there is a lot of discussion about how often companies come in with world-exclusive items specifically at Gen-Con, and if you are the kind of person who thrives on trying out new things at the earliest possible opportunity, you can imagine the thrill of being one of only like 50 people to own the developers' personal copies of a new game that arrived before the final shipment from China gets there, or whatever.

Not to mention all the reselling that goes on when people rush the lines and buy as many of these world-exclusives as possible and flip them for double or triple the price on EBay to other people who cannot wait but also could not attend.

Yes, this sounds kind of like an argument to avoid the initial hall rush ;)  I still line up as soon as possible myself, but that is because I wait all year to get into that beautiful Exhibition Hall, so why wait any longer?

Personally I do the rush to do the rush. To me it's part of the experience of Gencon and I've done it all 10+ years I've been. I could really care less about getting the first copies of some game or whatever else. I love the atmosphere, the feeling of the crowd. It's a shared moment in our hobby, something I thrive on (hence why I roleplay).

Thursday used to be considered the "light" day in the dealer hall. However in the past 5 or so years Thursday is as packed as any other day. However Saturday is still the worst day to be in the hall.
While I understand why some people have to be at the front of the stampede when the hall opens on Wednesday. It is much more relaxing to wait until the cattle go into the hall and then go in after things calm down.
We like to stand on the second floor overlook and "moo" at the people rushing into the hall.
Have Fun!