Some have been speculating the show will be on the 8th, so that Spiderman 2 and maybe Wolverine can be at the Disney Gaming show that's on the 9th.Kinda makes sense.
I feel like that probably isn't a factor, but I could see Sony going for more attention. Easy marketing.
But if that's the case then I feel like September 1st/2nd would be more likely. There's an Apple Event on the 7th, so that week is kind of busy.
Or maybe the disney show is the only show. Spider and wolfy will be there and that's that.